The New Sudoku Players' Forum

[Mathimagics]

Is the above clear?

Yes! I thank you …

Before we go on, it's probably worth reviewing just how my existing ED catalog is organised. The 5.47 billion grids are all in CF, and are ordered. Physically there is a separate file for each band, but logically they are an ordered set of 5.47 billion grids.

Given an arbitrary grid G, in CF, I identify its index number ID(G) by a binary search on the applicable band. A function FindGrid(G) returns ID(G), and is optimised assuming that the candidate grids for which we need to find GN's are themselves ordered. Tables of # of grids in each band, first grid in band, last grid in band, all assist with this process. Bands are loaded on demand, so the more catalog updates we can assemble and order to form a batch, the less the number of passes we need to make through the bands.

Also, I have to point out that my objective is actually slightly different to the one you have given. I want more than the final count table, I want to store an exemplar puzzle for each grid, reflecting the best known N for that grid in a self-evident fashion.

For any arbitrary puzzle X, we first convert it to G+P, where G is the solution in CF, and P has unique solution G. We get ID(G) from the ED catalog, and this tells exactly where to find its entry in the LCTP catalog. This will be G if no puzzle yet recorded, or a puzzle B, the best-so-far puzzle found. If P is better then we update the entry.

This means (in current model) it is a simple matter to add information for say, coloin's 18C collection - we create a batch file for the collection and just include that batch in our update procedure - this performs updates via a single pass over the bands by merging up to 64 batches of potentially new grids/puzzles.

I'm just reviewing where I am currently at, not arguing with your method. Over to you!

[Mathimagics]

I know that after my suggestions for UA scanning , you will try to do exactly the opposite of what I wrote here. On your place I would do the same.

Given my well-known tendency for blunders (search "humiliation" + userid="mathimagics"), and also considering your track record, I think you can safely assume that I do consider all of your suggestions very seriously!

The most important thing in this data model (beyond the puzzles generation) is obtaining the grid index, right?
My point is that the binary search isn't effective for huge files, but is very effective for chunks that fit in RAM.

Yes, the critical operation is finding the grid index.

But I have 32Gb of RAM, and the largest band (Band 6) file is less than 8Gb, so I can keep both the ED catalog (used for the index finding), AND the LCTP copy both in RAM and still only use 50% of memory.

That's why I decided not to re-organise the band-based catalog (I have already merged most of the high-end smaller bands, so my catalog actually has just 255 "bands").

It could probably be improved by having more evenly balanced files, but all the evidence suggests that the real bottleneck for the batch update process is not the binary search, but getting the bands in and out of memory. Search times for the indexing operation represent perhaps less than 5% of the overall time for the job.

For example, I'm getting load times that are at best 140MB/s. So I takes at least 15s to load a 2Gb band. This seems sluggish and I'm looking for a better method (than conventional binary file IO) … I tried using memory-mapped file method (MapViewOfFile) but that seemed to make little difference. Any suggestions here would be useful …

(PS: Thanks for the CoreUtils info, I will try them out …)

[EDIT] I did find one way to improve the band load time! Excluding the catalog folders from Window Defender seems to have perked it up somewhat …. Band 6 (7GB) loaded in 13s

[Mathimagics]

Are you hoping for hundreds or for zillions?

As many as you can come up with! Estimates suggest 30% of ED grids have 18C puzzles - so perhaps 2 billion - this makes 18 the worst-case of all. 17C, 19C, 20C are all "nice" cases, since we expect "almost all" grids to have no 17C, but will have 19C/20C. So any 18's that you can find are going to save time when the project eventually moves on to looking at 18C's.

I think its worthwhile for now for Mathimagics project to try to find any more grids without a 20 ... [if any]
The generation process is certainly fast for 20s and probably will get almost all the grids.

Im thinking that not many grids will only have a solitary 20 .... most grids will have plenty of 20s ? - aside from those automorphic grids which have reduced numbers of puzzles but we will see.

Indeed we will. blue has already checked the automorphic grids and identified just 4 grids with no 20C puzzle. I am hoping LCTP-20 will eventually give us a suitably small pool of non-automorphic grids that need a closer look at (ie that we can't find 20C puzzles for by any of the usual methods).

[Mathimagics]

Thanks very much to blue for those figures (and the links)!

100,000,000 samples, and every one had a 20, putting the "21, but no 20" count at "no more than 164" (with 95% confidence, I think).

Extremely useful information for the LCT-20 project ...

Cheers!
MM

[Mathimagics]

.
LCT-20 project has reached its first milestone. We've hit 50% of the ED grids, yay!!

This has taken a month, but with fits and starts, not to mention MS Windows Update murdering my workforce at regular intervals ....

Anyway, currently we have 20C or better puzzles recorded for 2,777,685,274 grids ( 50.8%).

A full report, by Band and number of clues, is given below. 17C puzzles from Mladen, 18/19C puzzle contributions are from coloin.
The % for each band reflects total puzzles for that band.

Worker productivity has been improved. Workers beaver away at 20C puzzle generation by morphing. Puzzles thus mined are reduced to batches containing 1 x 20C puzzle for each different ED grid. Productivity is measured by the daily batch sizes.

Duplicate grid rates - when different worker processes "solve" the same ED grid - are fairly good. In any set of up to 64 batches, around 75-80% of the grids are distinct.

The catalog update process takes these batches (up to 64 at a time) and updates the catalog. Overall yield, the key indicator during this phase, is measured by the % of distinct grids in a batch set for which puzzles have not already been found.

The first such set had a yield of 100% ( amazing, huh??). This had declined to 67% by the time we had found puzzles for 25% of the grids. Now we have 50% of grids found, and the yield has declined to 35%. These rates appear to be just what one would expect, although I would of course leave any definitive statements in this area to the Sultan of Sampling (blue).

Mladen, I'm sure, will be pleased to know that the old workforce has been sacked, and the new workers do all sort/merge operations via qsort, ie in memory. One short burst of I/O of course to write the batch to disk. Each worker now produces 40-50 million distinct grid/puzzles per day, and I now have 5 of them running.

I have also discovered, to my horror, that the update process is heavily handicapped by the fact that drive D, on which the ED and LCT catalog files reside, is REALLY slow for read/write operations compared to C, my primary drive. But C is only 0.5TB and 50% full, so it can't hold even one of these catalogs completely (they are each 420GB). But I did at least get noticably reduced update-pass times by moving the 1st 100 bands (75%) of the LCT catalog (for which both read and write acess are needed) to the primary drive.

Cheers!
MM

Band/Puzzle counts: Show

Code: Select all

  Band001:  ng =   1007170, 17c =    13, 18c =    460, 19c =      119, 20c =    479402, 21c =   0  ( 47.66%)
  Band002:  ng =  25502082, 17c =   408, 18c =  13636, 19c =     4716, 20c =  14286356, 21c =   0  ( 56.09%)
  Band003:  ng =  16538087, 17c =   281, 18c =   9941, 19c =     3377, 20c =  10027112, 21c =   0  ( 60.71%)
  Band004:  ng =   8417906, 17c =   129, 18c =   4296, 19c =     1349, 20c =   4677532, 21c =   0  ( 55.64%)
  Band005:  ng =  48737791, 17c =  1039, 18c =  35886, 19c =    11827, 20c =  31270283, 21c =   0  ( 64.26%)
  Band006:  ng =  96229042, 17c =  2146, 18c =  70270, 19c =    21174, 20c =  61443486, 21c =   0  ( 63.95%)
  Band007:  ng =  15765443, 17c =   393, 18c =  15022, 19c =     3608, 20c =  11019815, 21c =   0  ( 70.02%)
  Band008:  ng =   5306280, 17c =    76, 18c =   2955, 19c =      943, 20c =   3181042, 21c =   0  ( 60.02%)
  Band009:  ng =   8136013, 17c =   263, 18c =   7162, 19c =     1523, 20c =   5121187, 21c =   0  ( 63.05%)
  Band010:  ng =  47174193, 17c =  1112, 18c =  37778, 19c =    10228, 20c =  30464057, 21c =   0  ( 64.68%)
  Band011:  ng =  46788396, 17c =  1590, 18c =  49500, 19c =    11056, 20c =  31972760, 21c =   0  ( 68.47%)
  Band012:  ng =  46177270, 17c =  1284, 18c =  41594, 19c =    10156, 20c =  30697248, 21c =   0  ( 66.59%)
  Band013:  ng =  15340394, 17c =   433, 18c =  14141, 19c =     3297, 20c =  10365057, 21c =   0  ( 67.68%)
  Band014:  ng =  45397270, 17c =  1181, 18c =  41303, 19c =     9311, 20c =  31213534, 21c =   0  ( 68.87%)
  Band015:  ng =  45600758, 17c =  1368, 18c =  44037, 19c =    10239, 20c =  30806610, 21c =   0  ( 67.68%)
  Band016:  ng =   1631576, 17c =    18, 18c =    906, 19c =      224, 20c =   1036168, 21c =   0  ( 63.58%)
  Band017:  ng =  15093541, 17c =   541, 18c =  18080, 19c =     3832, 20c =  10738858, 21c =   0  ( 71.30%)
  Band018:  ng =  45101600, 17c =   761, 18c =  27622, 19c =     9399, 20c =  28185393, 21c =   0  ( 62.58%)
  Band019:  ng =  44832423, 17c =   909, 18c =  34251, 19c =    10373, 20c =  29048416, 21c =   0  ( 64.89%)
  Band020:  ng =  88782526, 17c =  2394, 18c =  83949, 19c =    19508, 20c =  60359460, 21c =   0  ( 68.10%)
  Band021:  ng =  44036568, 17c =   815, 18c =  28042, 19c =     9467, 20c =  27552699, 21c =   0  ( 62.65%)
  Band022:  ng =  85627559, 17c =  2080, 18c =  73122, 19c =    20119, 20c =  59135149, 21c =   0  ( 69.17%)
  Band023:  ng =  42711122, 17c =   819, 18c =  29837, 19c =    10058, 20c =  28199380, 21c =   0  ( 66.12%)
  Band024:  ng =  85102373, 17c =  1956, 18c =  70113, 19c =    19192, 20c =  58238205, 21c =   0  ( 68.54%)
  Band025:  ng =  41847039, 17c =  1040, 18c =  36762, 19c =     9486, 20c =  29179536, 21c =   0  ( 69.84%)
  Band026:  ng =  41335391, 17c =  1120, 18c =  39718, 19c =     8868, 20c =  29302490, 21c =   0  ( 71.01%)
  Band027:  ng =   4455504, 17c =    85, 18c =   2794, 19c =      918, 20c =   2987213, 21c =   0  ( 67.13%)
  Band028:  ng =  41102914, 17c =   860, 18c =  31422, 19c =     9653, 20c =  28156964, 21c =   0  ( 68.61%)
  Band029:  ng =   4591391, 17c =   132, 18c =   4693, 19c =     1021, 20c =   3286598, 21c =   0  ( 71.71%)
  Band030:  ng =   4664261, 17c =    86, 18c =   3182, 19c =      942, 20c =   3114069, 21c =   0  ( 66.85%)
  Band031:  ng =  13606209, 17c =   389, 18c =  12592, 19c =     3372, 20c =   9898517, 21c =   0  ( 72.87%)
  Band032:  ng =  40697707, 17c =    51, 18c =   3675, 19c =     1475, 20c =  13890667, 21c =   0  ( 34.14%)
  Band033:  ng =  80468663, 17c =    51, 18c =   5799, 19c =     2490, 20c =  22838341, 21c =   0  ( 28.39%)
  Band034:  ng =  79175610, 17c =   230, 18c =  12662, 19c =     4980, 20c =  34373888, 21c =   0  ( 43.44%)
  Band035:  ng =  77979783, 17c =   179, 18c =  11283, 19c =     5044, 20c =  31128328, 21c =   0  ( 39.94%)
  Band036:  ng =  38536298, 17c =    91, 18c =   4752, 19c =     1900, 20c =  15402337, 21c =   0  ( 39.99%)
  Band037:  ng =  76146967, 17c =   216, 18c =  11267, 19c =     4716, 20c =  33242871, 21c =   0  ( 43.68%)
  Band038:  ng =  74505665, 17c =   250, 18c =  12311, 19c =     4512, 20c =  32931870, 21c =   0  ( 44.22%)
  Band039:  ng =  74154564, 17c =   175, 18c =   9139, 19c =     3855, 20c =  28363062, 21c =   0  ( 38.27%)
  Band040:  ng =  72171447, 17c =   353, 18c =  18048, 19c =     5833, 20c =  36763243, 21c =   0  ( 50.97%)
  Band041:  ng =  36053455, 17c =   161, 18c =   8080, 19c =     2658, 20c =  17265792, 21c =   0  ( 47.92%)
  Band042:  ng =  70552290, 17c =   147, 18c =   7411, 19c =     3165, 20c =  27837830, 21c =   0  ( 39.47%)
  Band043:  ng =  69437575, 17c =   237, 18c =  11675, 19c =     3974, 20c =  30294633, 21c =   0  ( 43.65%)
  Band044:  ng =  67978951, 17c =   135, 18c =   9600, 19c =     3770, 20c =  27931581, 21c =   0  ( 41.11%)
  Band045:  ng =  33904021, 17c =    38, 18c =   2498, 19c =     1251, 20c =  10958902, 21c =   0  ( 32.33%)
  Band046:  ng =  66337407, 17c =   116, 18c =   7561, 19c =     3590, 20c =  25312177, 21c =   0  ( 38.17%)
  Band047:  ng =  65880161, 17c =   147, 18c =   9253, 19c =     4447, 20c =  27165343, 21c =   0  ( 41.26%)
  Band048:  ng =  64996381, 17c =    66, 18c =   3983, 19c =     2155, 20c =  18952084, 21c =   0  ( 29.17%)
  Band049:  ng =  63898062, 17c =   163, 18c =   8613, 19c =     4264, 20c =  25816936, 21c =   0  ( 40.42%)
  Band050:  ng =  62192220, 17c =   363, 18c =  17904, 19c =     5579, 20c =  33124077, 21c =   0  ( 53.30%)
  Band051:  ng =  61691475, 17c =   181, 18c =   9922, 19c =     3953, 20c =  27164436, 21c =   0  ( 44.06%)
  Band052:  ng =  60192385, 17c =   208, 18c =  10660, 19c =     3928, 20c =  27871779, 21c =   0  ( 46.33%)
  Band053:  ng =  29966384, 17c =   159, 18c =   7856, 19c =     2737, 20c =  15267101, 21c =   0  ( 50.98%)
  Band054:  ng =  29734495, 17c =    41, 18c =   1717, 19c =      947, 20c =   9600745, 21c =   0  ( 32.30%)
  Band055:  ng =  58731513, 17c =   228, 18c =  11137, 19c =     3970, 20c =  26942611, 21c =   0  ( 45.90%)
  Band056:  ng =  57263818, 17c =   370, 18c =  17351, 19c =     5761, 20c =  29422078, 21c =   0  ( 51.42%)
  Band057:  ng =  57033275, 17c =   182, 18c =   9872, 19c =     3904, 20c =  24319463, 21c =   0  ( 42.67%)
  Band058:  ng =  55394556, 17c =   153, 18c =   8882, 19c =     3790, 20c =  24429422, 21c =   0  ( 44.12%)
  Band059:  ng =  55022930, 17c =   143, 18c =   7547, 19c =     3465, 20c =  22945540, 21c =   0  ( 41.72%)
  Band060:  ng =  54018514, 17c =   243, 18c =  14132, 19c =     4963, 20c =  26037924, 21c =   0  ( 48.24%)
  Band061:  ng =  52964870, 17c =   337, 18c =  15009, 19c =     4828, 20c =  27530783, 21c =   0  ( 52.02%)
  Band062:  ng =  52242492, 17c =   139, 18c =   8853, 19c =     3668, 20c =  22378285, 21c =   0  ( 42.86%)
  Band063:  ng =  51245000, 17c =   204, 18c =   9429, 19c =     3395, 20c =  23451550, 21c =   0  ( 45.79%)
  Band064:  ng =  50540742, 17c =   206, 18c =   9004, 19c =     3586, 20c =  23757983, 21c =   0  ( 47.03%)
  Band065:  ng =  49644127, 17c =   324, 18c =  15803, 19c =     4982, 20c =  26695548, 21c =   0  ( 53.82%)
  Band066:  ng =  49190978, 17c =   121, 18c =   8652, 19c =     3301, 20c =  21278454, 21c =   0  ( 43.28%)
  Band067:  ng =  24077300, 17c =    41, 18c =   2080, 19c =     1019, 20c =   8200296, 21c =   0  ( 34.07%)
  Band068:  ng =  47978806, 17c =   278, 18c =  13128, 19c =     4362, 20c =  24445991, 21c =   0  ( 50.99%)
  Band069:  ng =  47059527, 17c =   137, 18c =   6706, 19c =     2796, 20c =  20815427, 21c =   0  ( 44.25%)
  Band070:  ng =  46231581, 17c =   254, 18c =  13026, 19c =     4737, 20c =  23910837, 21c =   0  ( 51.76%)
  Band071:  ng =  22715795, 17c =    79, 18c =   3757, 19c =     1520, 20c =   9562999, 21c =   0  ( 42.12%)
  Band072:  ng =  44778204, 17c =    87, 18c =   4951, 19c =     1820, 20c =  15684187, 21c =   0  ( 35.04%)
  Band073:  ng =  44053469, 17c =   189, 18c =   8539, 19c =     2948, 20c =  20720301, 21c =   0  ( 47.06%)
  Band074:  ng =  43401907, 17c =    54, 18c =   2824, 19c =     1382, 20c =  14909034, 21c =   0  ( 34.36%)
  Band075:  ng =  21398806, 17c =    46, 18c =   2470, 19c =     1223, 20c =   8883605, 21c =   0  ( 41.53%)
  Band076:  ng =  42061440, 17c =   171, 18c =   9363, 19c =     3054, 20c =  20477678, 21c =   0  ( 48.72%)
  Band077:  ng =  41316125, 17c =   191, 18c =   9269, 19c =     2936, 20c =  19821957, 21c =   0  ( 48.01%)
  Band078:  ng =  40571245, 17c =   143, 18c =   7928, 19c =     2943, 20c =  19129846, 21c =   0  ( 47.18%)
  Band079:  ng =  40282447, 17c =   178, 18c =   9815, 19c =     4094, 20c =  20117026, 21c =   0  ( 49.97%)
  Band080:  ng =  39233218, 17c =   182, 18c =   8537, 19c =     3028, 20c =  18192373, 21c =   0  ( 46.40%)
  Band081:  ng =  38522319, 17c =   176, 18c =   7729, 19c =     2559, 20c =  17021088, 21c =   0  ( 44.21%)
  Band082:  ng =  37881913, 17c =   126, 18c =   6273, 19c =     2208, 20c =  16066798, 21c =   0  ( 42.44%)
  Band083:  ng =  37460193, 17c =    38, 18c =   1852, 19c =     1184, 20c =  11006807, 21c =   0  ( 29.39%)
  Band084:  ng =  18460204, 17c =    28, 18c =   1520, 19c =      979, 20c =   6851526, 21c =   0  ( 37.13%)
  Band085:  ng =  36127803, 17c =   265, 18c =  12192, 19c =     3843, 20c =  19492665, 21c =   0  ( 54.00%)
  Band086:  ng =  35584769, 17c =   203, 18c =   8873, 19c =     2944, 20c =  17440146, 21c =   0  ( 49.04%)
  Band087:  ng =  34821531, 17c =   132, 18c =   6432, 19c =     2599, 20c =  16303227, 21c =   0  ( 46.85%)
  Band088:  ng =  34334716, 17c =   109, 18c =   5629, 19c =     2526, 20c =  16028395, 21c =   0  ( 46.71%)
  Band089:  ng =  33769162, 17c =   239, 18c =  11487, 19c =     3565, 20c =  18257522, 21c =   0  ( 54.11%)
  Band090:  ng =  33174401, 17c =   118, 18c =   6440, 19c =     2504, 20c =  15113990, 21c =   0  ( 45.59%)
  Band091:  ng =  32520037, 17c =   113, 18c =   5895, 19c =     2385, 20c =  14935272, 21c =   0  ( 45.95%)
  Band092:  ng =  31945541, 17c =   102, 18c =   4873, 19c =     2505, 20c =  14298288, 21c =   0  ( 44.78%)
  Band093:  ng =  31221072, 17c =    55, 18c =   3784, 19c =     1367, 20c =  11387577, 21c =   0  ( 36.49%)
  Band094:  ng =  30579410, 17c =    77, 18c =   3685, 19c =     1591, 20c =  13462825, 21c =   0  ( 44.04%)
  Band095:  ng =  29977732, 17c =    99, 18c =   5250, 19c =     1890, 20c =  13587373, 21c =   0  ( 45.35%)
  Band096:  ng =  29390061, 17c =   179, 18c =   6547, 19c =     2596, 20c =  14868232, 21c =   0  ( 50.62%)
  Band097:  ng =  14518368, 17c =    33, 18c =   1706, 19c =      734, 20c =   6402239, 21c =   0  ( 44.11%)
  Band098:  ng =  14372444, 17c =    36, 18c =   1889, 19c =      703, 20c =   6314373, 21c =   0  ( 43.95%)
  Band099:  ng =  28268021, 17c =   138, 18c =   6335, 19c =     2305, 20c =  14230046, 21c =   0  ( 50.37%)
  Band100:  ng =  27849953, 17c =    47, 18c =   1827, 19c =      939, 20c =   9148565, 21c =   0  ( 32.86%)
  Band101:  ng =  13768854, 17c =    20, 18c =    700, 19c =      500, 20c =   4614823, 21c =   0  ( 33.53%)
  Band102:  ng =  26929453, 17c =    77, 18c =   4529, 19c =     1639, 20c =  12383438, 21c =   0  ( 46.01%)
  Band103:  ng =  26382806, 17c =   102, 18c =   4959, 19c =     1867, 20c =  13182978, 21c =   0  ( 49.99%)
  Band104:  ng =   4359314, 17c =     5, 18c =    262, 19c =       99, 20c =   1436872, 21c =   0  ( 32.97%)
  Band105:  ng =  25997296, 17c =    17, 18c =   1204, 19c =      702, 20c =   8023455, 21c =   0  ( 30.87%)
  Band106:  ng =  25467197, 17c =   158, 18c =   7336, 19c =     2133, 20c =  13577445, 21c =   0  ( 53.35%)
  Band107:  ng =  24888528, 17c =   212, 18c =   9982, 19c =     3135, 20c =  14800090, 21c =   0  ( 59.52%)
  Band108:  ng =  24423300, 17c =   115, 18c =   5007, 19c =     1885, 20c =  12166079, 21c =   0  ( 49.84%)
  Band109:  ng =  23988326, 17c =    77, 18c =   2917, 19c =     1386, 20c =  10242971, 21c =   0  ( 42.72%)
  Band110:  ng =  23541927, 17c =   101, 18c =   5151, 19c =     1996, 20c =  11872006, 21c =   0  ( 50.46%)
  Band111:  ng =  23070530, 17c =   119, 18c =   6887, 19c =     2345, 20c =  12004870, 21c =   0  ( 52.08%)
  Band112:  ng =  22609142, 17c =    89, 18c =   4676, 19c =     1950, 20c =  11372911, 21c =   0  ( 50.33%)
  Band113:  ng =  22100458, 17c =   135, 18c =   6110, 19c =     1896, 20c =  11675658, 21c =   0  ( 52.87%)
  Band114:  ng =  10879514, 17c =    54, 18c =   2157, 19c =      774, 20c =   5257321, 21c =   0  ( 48.35%)
  Band115:  ng =  21378062, 17c =    70, 18c =   2785, 19c =     1190, 20c =   9490617, 21c =   0  ( 44.41%)
  Band116:  ng =  20985174, 17c =    65, 18c =   3167, 19c =     1117, 20c =   8491224, 21c =   0  ( 40.48%)
  Band117:  ng =  20674972, 17c =   219, 18c =   9962, 19c =     2738, 20c =  12377413, 21c =   0  ( 59.93%)
  Band118:  ng =  20107116, 17c =   299, 18c =  10035, 19c =     2639, 20c =  12567780, 21c =   0  ( 62.57%)
  Band119:  ng =  19854606, 17c =    68, 18c =   3072, 19c =     1270, 20c =   9083430, 21c =   0  ( 45.77%)
  Band120:  ng =   9732970, 17c =   142, 18c =   6039, 19c =     1325, 20c =   6105899, 21c =   0  ( 62.81%)
  Band121:  ng =  19084488, 17c =   250, 18c =   9637, 19c =     2554, 20c =  11809486, 21c =   0  ( 61.95%)
  Band122:  ng =   9491325, 17c =    21, 18c =   1003, 19c =      406, 20c =   3642948, 21c =   0  ( 38.40%)
  Band123:  ng =  18532281, 17c =    98, 18c =   5187, 19c =     1880, 20c =  10019028, 21c =   0  ( 54.10%)
  Band124:  ng =   9142485, 17c =    28, 18c =   1944, 19c =      752, 20c =   4363982, 21c =   0  ( 47.76%)
  Band125:  ng =  18075269, 17c =   192, 18c =   8838, 19c =     2529, 20c =  10901181, 21c =   0  ( 60.37%)
  Band126:  ng =  17675306, 17c =   113, 18c =   5773, 19c =     1827, 20c =   9665349, 21c =   0  ( 54.73%)
  Band127:  ng =  17545752, 17c =    75, 18c =   4093, 19c =     1594, 20c =   8767802, 21c =   0  ( 50.00%)
  Band128:  ng =  16990098, 17c =   110, 18c =   5125, 19c =     1825, 20c =   9896831, 21c =   0  ( 58.29%)
  Band129:  ng =   8369473, 17c =    27, 18c =   1314, 19c =      558, 20c =   4020157, 21c =   0  ( 48.06%)
  Band130:  ng =  16406705, 17c =   196, 18c =   8260, 19c =     2181, 20c =  10211449, 21c =   0  ( 62.30%)
  Band131:  ng =  16189996, 17c =    61, 18c =   3771, 19c =     1316, 20c =   8364135, 21c =   0  ( 51.69%)
  Band132:  ng =  15791769, 17c =    66, 18c =   2685, 19c =     1130, 20c =   7544699, 21c =   0  ( 47.80%)
  Band133:  ng =   2613345, 17c =     1, 18c =    121, 19c =       90, 20c =    886362, 21c =   0  ( 33.92%)
  Band134:  ng =  15362664, 17c =   168, 18c =   6809, 19c =     1929, 20c =   9495805, 21c =   0  ( 61.87%)
  Band135:  ng =  15272476, 17c =    73, 18c =   3565, 19c =     1306, 20c =   7602988, 21c =   0  ( 49.81%)
  Band136:  ng =  14918036, 17c =    67, 18c =   3793, 19c =     1287, 20c =   7594343, 21c =   0  ( 50.94%)
  Band137:  ng =   7254450, 17c =    21, 18c =   1209, 19c =      531, 20c =   3468494, 21c =   0  ( 47.84%)
  Band138:  ng =  14383075, 17c =   150, 18c =   6458, 19c =     1810, 20c =   8418163, 21c =   0  ( 58.59%)
  Band139:  ng =   7011714, 17c =    71, 18c =   3675, 19c =      939, 20c =   4376145, 21c =   0  ( 62.48%)
  Band140:  ng =  13738161, 17c =    39, 18c =   2560, 19c =      891, 20c =   6149123, 21c =   0  ( 44.78%)
  Band141:  ng =  13445152, 17c =    95, 18c =   5291, 19c =     1858, 20c =   8036322, 21c =   0  ( 59.83%)
  Band142:  ng =   6593805, 17c =    64, 18c =   3072, 19c =      947, 20c =   4085220, 21c =   0  ( 62.02%)
  Band143:  ng =  12918117, 17c =   124, 18c =   5963, 19c =     1929, 20c =   8266458, 21c =   0  ( 64.05%)
  Band144:  ng =   6403269, 17c =    44, 18c =   2131, 19c =      759, 20c =   3802884, 21c =   0  ( 59.44%)
  Band145:  ng =  12568136, 17c =   176, 18c =   6612, 19c =     2087, 20c =   8451009, 21c =   0  ( 67.31%)
  Band146:  ng =  12354720, 17c =   109, 18c =   4949, 19c =     1729, 20c =   7823073, 21c =   0  ( 63.38%)
  Band147:  ng =  12036469, 17c =    95, 18c =   4378, 19c =     1452, 20c =   7364091, 21c =   0  ( 61.23%)
  Band148:  ng =   5931073, 17c =    25, 18c =   1121, 19c =      421, 20c =   3094839, 21c =   0  ( 52.21%)
  Band149:  ng =   5949060, 17c =    29, 18c =   1437, 19c =      572, 20c =   3161190, 21c =   0  ( 53.17%)
  Band150:  ng =  11577852, 17c =    83, 18c =   4573, 19c =     1705, 20c =   7105868, 21c =   0  ( 61.43%)
  Band151:  ng =  11435633, 17c =    56, 18c =   3109, 19c =     1268, 20c =   6303771, 21c =   0  ( 55.16%)
  Band152:  ng =  11155974, 17c =    42, 18c =   2566, 19c =      921, 20c =   5252546, 21c =   0  ( 47.11%)
  Band153:  ng =  10671486, 17c =   154, 18c =   5387, 19c =     1513, 20c =   7120876, 21c =   0  ( 66.79%)
  Band154:  ng =  10525735, 17c =   114, 18c =   5195, 19c =     1628, 20c =   7055740, 21c =   0  ( 67.10%)
  Band155:  ng =  10188634, 17c =   164, 18c =   7145, 19c =     1970, 20c =   7248404, 21c =   0  ( 71.23%)
  Band156:  ng =  10059617, 17c =    86, 18c =   3821, 19c =     1358, 20c =   6302193, 21c =   0  ( 62.70%)
  Band157:  ng =   9805813, 17c =   106, 18c =   4586, 19c =     1190, 20c =   6109357, 21c =   0  ( 62.36%)
  Band158:  ng =   9629320, 17c =    55, 18c =   3595, 19c =     1447, 20c =   5780887, 21c =   0  ( 60.09%)
  Band159:  ng =   9490222, 17c =    92, 18c =   4224, 19c =     1588, 20c =   5938180, 21c =   0  ( 62.63%)
  Band160:  ng =   9280124, 17c =    30, 18c =   2407, 19c =     1056, 20c =   5054048, 21c =   0  ( 54.50%)
  Band161:  ng =   8844112, 17c =    70, 18c =   3697, 19c =     1336, 20c =   5512140, 21c =   0  ( 62.38%)
  Band162:  ng =   8628099, 17c =   110, 18c =   5674, 19c =     1777, 20c =   5978642, 21c =   0  ( 69.38%)
  Band163:  ng =   8429593, 17c =    85, 18c =   3834, 19c =     1164, 20c =   5250869, 21c =   0  ( 62.35%)
  Band164:  ng =   8227144, 17c =    56, 18c =   3198, 19c =     1157, 20c =   5168776, 21c =   0  ( 62.88%)
  Band165:  ng =   7998287, 17c =   140, 18c =   6194, 19c =     1713, 20c =   5686631, 21c =   0  ( 71.20%)
  Band166:  ng =   7813413, 17c =    79, 18c =   3553, 19c =     1223, 20c =   5054774, 21c =   0  ( 64.76%)
  Band167:  ng =   3839149, 17c =    47, 18c =   1662, 19c =      506, 20c =   2372602, 21c =   0  ( 61.86%)
  Band168:  ng =   7548052, 17c =   171, 18c =   6736, 19c =     1560, 20c =   5384748, 21c =   0  ( 71.45%)
  Band169:  ng =   7349287, 17c =   154, 18c =   5234, 19c =     1587, 20c =   5171350, 21c =   0  ( 70.46%)
  Band170:  ng =   7146807, 17c =    98, 18c =   5405, 19c =     1267, 20c =   5075212, 21c =   0  ( 71.11%)
  Band171:  ng =   6993422, 17c =    44, 18c =   2072, 19c =      637, 20c =   3642555, 21c =   0  ( 52.12%)
  Band172:  ng =   6828801, 17c =    61, 18c =   2778, 19c =      837, 20c =   4232380, 21c =   0  ( 62.03%)
  Band173:  ng =   6674911, 17c =    67, 18c =   2955, 19c =     1019, 20c =   4300689, 21c =   0  ( 64.49%)
  Band174:  ng =   6476248, 17c =    37, 18c =   1836, 19c =      683, 20c =   3678255, 21c =   0  ( 56.84%)
  Band175:  ng =   3166465, 17c =    33, 18c =   1330, 19c =      425, 20c =   1936999, 21c =   0  ( 61.23%)
  Band176:  ng =   6205963, 17c =    98, 18c =   4404, 19c =     1156, 20c =   4339426, 21c =   0  ( 70.01%)
  Band177:  ng =   6040631, 17c =   115, 18c =   4556, 19c =     1271, 20c =   4253121, 21c =   0  ( 70.51%)
  Band178:  ng =   5882934, 17c =    80, 18c =   3450, 19c =     1061, 20c =   3903875, 21c =   0  ( 66.44%)
  Band179:  ng =   5812748, 17c =    88, 18c =   4410, 19c =     1154, 20c =   4025002, 21c =   0  ( 69.34%)
  Band180:  ng =   5615082, 17c =    66, 18c =   3098, 19c =      903, 20c =   3646291, 21c =   0  ( 65.01%)
  Band181:  ng =   5461387, 17c =    62, 18c =   2673, 19c =      896, 20c =   3519107, 21c =   0  ( 64.50%)
  Band182:  ng =   5367414, 17c =    35, 18c =   1555, 19c =      608, 20c =   2981436, 21c =   0  ( 55.59%)
  Band183:  ng =   5222068, 17c =    12, 18c =    636, 19c =      305, 20c =   2180786, 21c =   0  ( 41.78%)
  Band184:  ng =   5072949, 17c =    84, 18c =   3168, 19c =      932, 20c =   3334555, 21c =   0  ( 65.81%)
  Band185:  ng =   4918277, 17c =   110, 18c =   3762, 19c =     1233, 20c =   3478049, 21c =   0  ( 70.82%)
  Band186:  ng =   4778878, 17c =    47, 18c =   2029, 19c =      804, 20c =   3005235, 21c =   0  ( 62.95%)
  Band187:  ng =   4641003, 17c =    38, 18c =   1740, 19c =      475, 20c =   2449845, 21c =   0  ( 52.84%)
  Band188:  ng =   4539624, 17c =    34, 18c =   1352, 19c =      523, 20c =   2605875, 21c =   0  ( 57.44%)
  Band189:  ng =   4407284, 17c =    28, 18c =   1247, 19c =      500, 20c =   2523539, 21c =   0  ( 57.30%)
  Band190:  ng =   2186822, 17c =    19, 18c =    810, 19c =      253, 20c =   1352360, 21c =   0  ( 61.89%)
  Band191:  ng =   4220821, 17c =    30, 18c =   1326, 19c =      482, 20c =   2465753, 21c =   0  ( 58.46%)
  Band192:  ng =   4158097, 17c =    21, 18c =   1413, 19c =      400, 20c =   2192492, 21c =   0  ( 52.77%)
  Band193:  ng =   4070158, 17c =    17, 18c =    995, 19c =      398, 20c =   2188257, 21c =   0  ( 53.80%)
  Band194:  ng =   3857103, 17c =    37, 18c =   1904, 19c =      570, 20c =   2571139, 21c =   0  ( 66.72%)
  Band195:  ng =   3785628, 17c =    19, 18c =   1165, 19c =      425, 20c =   2189558, 21c =   0  ( 57.88%)
  Band196:  ng =   3693474, 17c =    27, 18c =   1253, 19c =      353, 20c =   1950292, 21c =   0  ( 52.85%)
  Band197:  ng =   3555681, 17c =    74, 18c =   2544, 19c =      604, 20c =   2430326, 21c =   0  ( 68.44%)
  Band198:  ng =   3453089, 17c =    32, 18c =   1991, 19c =      592, 20c =   2267601, 21c =   0  ( 65.74%)
  Band199:  ng =   3345667, 17c =    80, 18c =   3087, 19c =      770, 20c =   2465293, 21c =   0  ( 73.80%)
  Band200:  ng =   3252227, 17c =    66, 18c =   3028, 19c =      880, 20c =   2325193, 21c =   0  ( 71.62%)
  Band201:  ng =   3165254, 17c =    82, 18c =   3186, 19c =      821, 20c =   2298148, 21c =   0  ( 72.73%)
  Band202:  ng =   3064062, 17c =    28, 18c =   1639, 19c =      490, 20c =   1945802, 21c =   0  ( 63.57%)
  Band203:  ng =   2966309, 17c =    34, 18c =   1603, 19c =      503, 20c =   1920702, 21c =   0  ( 64.82%)
  Band204:  ng =   2932890, 17c =    33, 18c =   1857, 19c =      491, 20c =   1902769, 21c =   0  ( 64.96%)
  Band205:  ng =   2841380, 17c =    36, 18c =   1504, 19c =      449, 20c =   1830898, 21c =   0  ( 64.51%)
  Band206:  ng =   2701985, 17c =    70, 18c =   2782, 19c =      732, 20c =   1988949, 21c =   0  ( 73.74%)
  Band207:  ng =   2628788, 17c =    71, 18c =   2535, 19c =      596, 20c =   1905760, 21c =   0  ( 72.62%)
  Band208:  ng =   2532198, 17c =    22, 18c =   1223, 19c =      405, 20c =   1674396, 21c =   0  ( 66.19%)
  Band209:  ng =   2443960, 17c =    43, 18c =   2210, 19c =      574, 20c =   1784475, 21c =   0  ( 73.13%)
  Band210:  ng =   1243959, 17c =    22, 18c =   1087, 19c =      251, 20c =    840882, 21c =   0  ( 67.71%)
  Band211:  ng =   2317171, 17c =    54, 18c =   2354, 19c =      597, 20c =   1718159, 21c =   0  ( 74.28%)
  Band212:  ng =   2357854, 17c =    52, 18c =   1975, 19c =      501, 20c =   1643530, 21c =   0  ( 69.81%)
  Band213:  ng =   1137589, 17c =     5, 18c =    291, 19c =      127, 20c =    624694, 21c =   0  ( 54.95%)
  Band214:  ng =   1083228, 17c =    11, 18c =    300, 19c =      139, 20c =    620938, 21c =   0  ( 57.36%)
  Band215:  ng =   2183311, 17c =    45, 18c =   1934, 19c =      492, 20c =   1515044, 21c =   0  ( 69.51%)
  Band216:  ng =   2244753, 17c =    38, 18c =   1737, 19c =      443, 20c =   1472784, 21c =   0  ( 65.71%)
  Band217:  ng =   2143677, 17c =    15, 18c =    578, 19c =      211, 20c =   1125983, 21c =   0  ( 52.56%)
  Band218:  ng =   2100798, 17c =     7, 18c =    599, 19c =      238, 20c =   1050939, 21c =   0  ( 50.07%)
  Band219:  ng =   1007465, 17c =     4, 18c =    233, 19c =       83, 20c =    414775, 21c =   0  ( 41.20%)
  Band220:  ng =   1970315, 17c =    11, 18c =    634, 19c =      278, 20c =    994205, 21c =   0  ( 50.51%)
  Band221:  ng =   1841722, 17c =    14, 18c =    886, 19c =      214, 20c =   1081861, 21c =   0  ( 58.80%)
  Band222:  ng =   1873099, 17c =    17, 18c =    804, 19c =      272, 20c =   1057947, 21c =   0  ( 56.54%)
  Band223:  ng =   1772301, 17c =    12, 18c =    573, 19c =      184, 20c =    929257, 21c =   0  ( 52.48%)
  Band224:  ng =    347777, 17c =     0, 18c =     29, 19c =       11, 20c =    104991, 21c =   0  ( 30.20%)
  Band225:  ng =   1968442, 17c =     6, 18c =    451, 19c =      211, 20c =    893516, 21c =   0  ( 45.43%)
  Band226:  ng =   1677704, 17c =     9, 18c =    567, 19c =      194, 20c =    896217, 21c =   0  ( 53.47%)
  Band227:  ng =   1521001, 17c =    17, 18c =    785, 19c =      222, 20c =    952542, 21c =   0  ( 62.69%)
  Band228:  ng =   1498734, 17c =    11, 18c =    602, 19c =      175, 20c =    867127, 21c =   0  ( 57.91%)
  Band229:  ng =   1515366, 17c =    22, 18c =    866, 19c =      274, 20c =    918310, 21c =   0  ( 60.68%)
  Band230:  ng =   1457098, 17c =    16, 18c =    446, 19c =      188, 20c =    787013, 21c =   0  ( 54.06%)
  Band231:  ng =   1331185, 17c =     8, 18c =    945, 19c =      248, 20c =    866091, 21c =   0  ( 65.15%)
  Band232:  ng =   1279569, 17c =     2, 18c =    482, 19c =      166, 20c =    735764, 21c =   0  ( 57.55%)
  Band233:  ng =   1262013, 17c =     9, 18c =    464, 19c =      196, 20c =    726803, 21c =   0  ( 57.64%)
  Band234:  ng =   1218744, 17c =    23, 18c =    892, 19c =      258, 20c =    808840, 21c =   0  ( 66.46%)
  Band235:  ng =    386642, 17c =     8, 18c =    339, 19c =       78, 20c =    260571, 21c =   0  ( 67.50%)
  Band236:  ng =   1182963, 17c =    22, 18c =   1394, 19c =      343, 20c =    826523, 21c =   0  ( 70.02%)
  Band237:  ng =    570172, 17c =     1, 18c =     37, 19c =       33, 20c =    210984, 21c =   0  ( 37.02%)
  Band238:  ng =   1111083, 17c =     2, 18c =    264, 19c =      122, 20c =    598554, 21c =   0  ( 53.91%)
  Band239:  ng =   1076551, 17c =    13, 18c =    644, 19c =      219, 20c =    697415, 21c =   0  ( 64.86%)
  Band240:  ng =    167032, 17c =     0, 18c =     21, 19c =       10, 20c =     74807, 21c =   0  ( 44.80%)
  Band241:  ng =    533940, 17c =     5, 18c =    295, 19c =      117, 20c =    358724, 21c =   0  ( 67.26%)
  Band242:  ng =   1048083, 17c =    15, 18c =    708, 19c =      264, 20c =    740972, 21c =   0  ( 70.79%)
  Band243:  ng =    974591, 17c =    19, 18c =    887, 19c =      319, 20c =    757254, 21c =   0  ( 77.83%)
  Band244:  ng =    967788, 17c =    18, 18c =    929, 19c =      350, 20c =    737096, 21c =   0  ( 76.30%)
  Band245:  ng =    455310, 17c =     2, 18c =    268, 19c =       92, 20c =    316309, 21c =   0  ( 69.55%)
  Band246:  ng =    915249, 17c =    12, 18c =    679, 19c =      188, 20c =    647105, 21c =   0  ( 70.80%)
  Band247:  ng =    500537, 17c =     4, 18c =    197, 19c =      107, 20c =    310954, 21c =   0  ( 62.19%)
  Band248:  ng =    783336, 17c =    22, 18c =   1140, 19c =      319, 20c =    657471, 21c =   0  ( 84.12%)
  Band249:  ng =    822496, 17c =    18, 18c =    867, 19c =      293, 20c =    645164, 21c =   0  ( 78.58%)
  Band250:  ng =   4118353, 17c =   102, 18c =   3683, 19c =     1224, 20c =   3084158, 21c =   0  ( 75.01%)
  Band260:  ng =   4942966, 17c =   141, 18c =   6288, 19c =     1796, 20c =   3999647, 21c =   0  ( 81.08%)
  Band270:  ng =   2374942, 17c =    80, 18c =   3356, 19c =      905, 20c =   1963304, 21c =   0  ( 82.85%)
  Band280:  ng =   1443458, 17c =    42, 18c =   1690, 19c =      502, 20c =   1163353, 21c =   0  ( 80.75%)
  Band290:  ng =   1584461, 17c =    63, 18c =   2328, 19c =      659, 20c =   1317673, 21c =   0  ( 83.35%)
  Band300:  ng =   2097068, 17c =   105, 18c =   4280, 19c =     1226, 20c =   1822620, 21c =   0  ( 87.18%)
------------------------------------------------------------------------------------------------------------
  Totals:       2780210148, 17c = 46300, 18c =1886437, 19c =   592137, 20c =2777685274, 21c =   0  ( 50.80%)


[Mathimagics]

I still can't realize how and why you organized the process by bands while mutations result in puzzles from random band. But I prefer explanation formulated at the final stages of the project, not now.

Ok, but I will say just this - my ED catalog was originally generated by gsf's sudoku tool, and I ran it once on each band, and stored each result set in a separate file. Cloning it to use as LCT catalog means that grid index lookup in ED also gives the file offset in LCT ...

Did you use the results from symmetrical 18's thread in this forum?

No, but I will certainly look in there at some stage. All 18C's and 19C's that I have recorded were all provided by coloin ...

[Mathimagics]

Some minor milestones reached for LCT-20 today ...

• total grids ticked off has passed the 3 billion mark ...

• we have 100% coverage for Bands 300 - 416. This is of course a very small subset (2,097,068 grids) but it's a first time outing for the stage 2 worker process, aka WorkerX - these workers implement stage 2 of the pool reduction process, in which we attempt to reduce the unresolved grids by explicitly targeting them, looking for 20C puzzles. (Stage 3, the final stage, will rigorously test unresolved grids via a "Checker"-like process to determine their final status).
  
  So we can state definitively that ALL grids in these bands have 20C or better puzzles.

The first version of WorkerX uses conventional weapons to find 20C puzzles on a grid - producing minimal puzzles by removing clues, repeating the process until we find a 20C or exceed an iteration limit. In this naive form, it is painfully slow, perhaps 0.3 grids/second, but with some simple improvements (reduce to 22C then do a limited vicinity search) it can be prodded into delivering aout 8 - 10 grids/sec. That would amount to a daily yield of 700K - 850K, so it suffices for now, it can finish off the smaller bands.

The real stage 2 work will require much heavier duty capability, and blue has indicated that we might get perhaps 200 grids/sec from code that he has, and has volunteered to consruct and deliver an app, and we very much look forward to that!

Meanwhile the stage 1 workers soldier on ... they are (rather amazingly) each still delivering between 15 and 20 million new grids a day (an effective yield of 170 - 230 new grids/second). This will inevitably decline, of course, but for now it's all systems go ...

Cheers,
MM

[EDIT] Today's bulk update results: now have 3,206,072,984 grids resolved ( 58.58%). Workers net yield (% of grids found that are new, ie unresolved) has dipped below 30% for the first time: 29.8%

[Mathimagics]

LCT-20 Progress Report 20 Jul 2019

• grids resolved = 3,424,231,060 (62.57%)

• workers yield 26.4%, 21 million new grids per worker per day

• blue has delivered his app, which we have christened BlueMagic20. It finds 20C puzzles if they exist for specific grids, and can do so at an astonishing rate of 16 million a day!

Thanks to him, we can now predict fairly accurately the time remaining. The stage 1 worker will run for another 3-5 days, until their yield declines to the point where they produce less than 16 million a day each, and we switch over to stage 2 and run BlueMagic20 instead. Completion times then become effectively linear, it just depends how many workers we can throw at it. But all indications point to completion within 14 days.

[Mathimagics]

OMG !!!

You mean to say, that should there exist a grid with 20C puzzles, but none with a 668 pattern, then I might have to waste 5-10 seconds of my precious time re-testing that grid with my NotMagic20 app?

And that this might involve testing potentially 1000's 100's dozens of grids?

I want a refund!

[Mathimagics]

His name should be Ozymandias: "Look at my run times, fellow coders, and despair ... "

[Mathimagics]

A minor milestone has been passed, the number of grids resolvedis now 3,880,139,870, which is a shade under 71%.

And the Stage 1 workers are still producing net yields that make me reluctant to kill them off and switch to Stage 2 (explicit grid testing with BlueMagic).

Productivity measures are quite rubbery here at the atomic level - the net grid rate can only be estimated, for various reasons. Administration is also complicated, again for various reasons. These vagaries will all go away when we switch to Stage 2 mode. We will have much more straight-forward DB admin and accurate timings available. But the overall progress is absolute, and indisputable ...

Despite dwindling net yields (only 20% of grids produced are new ones), these hard-working souls have delivered 460 million new grid resolutions since July 20, 5 days ago. That's the equivalent of 18 million per day per worker. This looks to have declined to 130 million for the past 2 days, but I can't kill off these guys just yet, not with those figures. And so, the execution is delayed for another 24/48 hours!

Will they survive long enough to see us safely though to the 4 billion mark? The entire planet holds its collective breath ...

[Mathimagics]

We now have 4,065,435,695 ( 74.3%) of grids resolved.

blue has kindly provided a library interface to the BlueMagic function which will greatly simplify the system admin side of the crossover to explicit grid testing (LCT-20 Stage 2). The old (Stage 1) worker processes will be replaced by new ones over the next couple of days.

Cheers
MM

[Mathimagics]

Ok, it's official! LCT-20 Stage 1 is over, with 75% of grids resolved: 4,107,224,495

The work force have been retired, given 3 weeks leave (unpaid), and will return for the LCT-19 job. They have resolved an impressive total of 800 million grids per week since the commencement (around 22 June).

Stage 2 has now commenced, with 5 workers using BlueMagic to find puzzles for the 1,365,506,043 unresolved grids.

Each should process 14-16 million grids a day, so that's at most 100 x worker-days to complete, with an eta of around 15 August looking very likely.

It is interesting that some of the bigger bands have quite low resolution rates, perhaps 50-55%, while most other bands have 80%+. Not sure if there's anything going on there ...

A full breakdown by band is included below (ng = grids in band, nu = grids unresolved). Note that Band files 250 - 300 are all multiband files (eg Band300 has grids with band index = 300 to 416).

Cheers
MM

Code: Select all

 Totals:
     17C:      46300
     18C:   10221135
     19C:    5626788
     20C: 4091330268
     21c:          4
          ----------
 Puzzles: 4107224495 (  75.05%)
     unk: 1365506043 (  24.95%)
          ----------
   Grids: 5472730538


Band status: Show

Code: Select all

c:\UA9\Find20C\Admin>count20c
Band range selected:   1 to 255
Processing (count mode)
 Band001:  ng =   1007170, nu =         0: 17c =    13, 18c =   3333, 19c =      697, 20c =    1003126, 21c =   1  (100.00%)
 Band002:  ng =  25502082, nu =   5340872: 17c =   408, 18c =  88102, 19c =    29977, 20c =   20042723, 21c =   0  ( 79.06%)
 Band003:  ng =  16538087, nu =   2858975: 17c =   281, 18c =  58532, 19c =    24849, 20c =   13595450, 21c =   0  ( 82.71%)
 Band004:  ng =   8417906, nu =   1804827: 17c =   129, 18c =  28636, 19c =    10510, 20c =    6573803, 21c =   1  ( 78.56%)
 Band005:  ng =  48737791, nu =   7162466: 17c =  1039, 18c = 205539, 19c =    94508, 20c =   41274239, 21c =   0  ( 85.30%)
 Band006:  ng =  96229042, nu =  14393253: 17c =  2146, 18c = 401009, 19c =   186984, 20c =   81245650, 21c =   0  ( 85.04%)
 Band007:  ng =  15765443, nu =   1718979: 17c =   393, 18c =  79818, 19c =    39910, 20c =   13926343, 21c =   0  ( 89.10%)
 Band008:  ng =   5306280, nu =    951699: 17c =    76, 18c =  18665, 19c =     8512, 20c =    4327328, 21c =   0  ( 82.06%)
 Band009:  ng =   8136013, nu =   1270070: 17c =   263, 18c =  37623, 19c =    13906, 20c =    6814151, 21c =   0  ( 84.39%)
 Band010:  ng =  47174193, nu =   6835086: 17c =  1112, 18c = 210041, 19c =    95986, 20c =   40031968, 21c =   0  ( 85.51%)
 Band011:  ng =  46788396, nu =   5562637: 17c =  1590, 18c = 246886, 19c =   109034, 20c =   40868249, 21c =   0  ( 88.11%)
 Band012:  ng =  46177270, nu =   6095597: 17c =  1284, 18c = 223388, 19c =   109106, 20c =   39747895, 21c =   0  ( 86.80%)
 Band013:  ng =  15340394, nu =   1916145: 17c =   433, 18c =  75035, 19c =    37823, 20c =   13310958, 21c =   0  ( 87.51%)
 Band014:  ng =  45397270, nu =   5332910: 17c =  1181, 18c = 226871, 19c =   117666, 20c =   39718642, 21c =   0  ( 88.25%)
 Band015:  ng =  45600758, nu =   5647495: 17c =  1368, 18c = 227186, 19c =   103652, 20c =   39621057, 21c =   0  ( 87.62%)
 Band016:  ng =   1631576, nu =         0: 17c =    18, 18c =   5707, 19c =     3998, 20c =    1621853, 21c =   0  (100.00%)
 Band017:  ng =  15093541, nu =   1523271: 17c =   541, 18c =  84939, 19c =    38837, 20c =   13445953, 21c =   0  ( 89.91%)
 Band018:  ng =  45101600, nu =   7112942: 17c =   761, 18c = 159014, 19c =    74459, 20c =   37754424, 21c =   0  ( 84.23%)
 Band019:  ng =  44832423, nu =   6307814: 17c =   909, 18c = 179947, 19c =    84023, 20c =   38259730, 21c =   0  ( 85.93%)
 Band020:  ng =  88782526, nu =  10590358: 17c =  2394, 18c = 421068, 19c =   185739, 20c =   77582967, 21c =   0  ( 88.07%)
 Band021:  ng =  44036568, nu =   6915808: 17c =   815, 18c = 160442, 19c =    76868, 20c =   36882635, 21c =   0  ( 84.30%)
 Band022:  ng =  85627559, nu =   9667103: 17c =  2080, 18c = 382056, 19c =   197580, 20c =   75378740, 21c =   0  ( 88.71%)
 Band023:  ng =  42711122, nu =   5640815: 17c =   819, 18c = 168178, 19c =    87585, 20c =   36813725, 21c =   0  ( 86.79%)
 Band024:  ng =  85102373, nu =   9921443: 17c =  1956, 18c = 374045, 19c =   192035, 20c =   74612894, 21c =   0  ( 88.34%)
 Band025:  ng =  41847039, nu =   4478585: 17c =  1040, 18c = 193762, 19c =    92752, 20c =   37080900, 21c =   0  ( 89.30%)
 Band026:  ng =  41335391, nu =   4152421: 17c =  1120, 18c = 202267, 19c =    97175, 20c =   36882408, 21c =   0  ( 89.95%)
 Band027:  ng =   4455504, nu =    554498: 17c =    85, 18c =  15020, 19c =     8978, 20c =    3876923, 21c =   0  ( 87.55%)
 Band028:  ng =  41102914, nu =   4699266: 17c =   860, 18c = 168139, 19c =    85534, 20c =   36149115, 21c =   0  ( 88.57%)
 Band029:  ng =   4591391, nu =    431588: 17c =   132, 18c =  22318, 19c =    10001, 20c =    4127352, 21c =   0  ( 90.60%)
 Band030:  ng =   4664261, nu =    592252: 17c =    86, 18c =  17328, 19c =     9450, 20c =    4045145, 21c =   0  ( 87.30%)
 Band031:  ng =  13606209, nu =   1211908: 17c =   389, 18c =  67031, 19c =    32343, 20c =   12294538, 21c =   0  ( 91.09%)
 Band032:  ng =  40697707, nu =  16850990: 17c =    51, 18c =  20440, 19c =    18125, 20c =   23808101, 21c =   0  ( 58.59%)
 Band033:  ng =  80468663, nu =  39014727: 17c =    51, 18c =  30778, 19c =    32125, 20c =   41390982, 21c =   0  ( 51.52%)
 Band034:  ng =  79175610, nu =  24402482: 17c =   230, 18c =  73557, 19c =    48788, 20c =   54650553, 21c =   0  ( 69.18%)
 Band035:  ng =  77979783, nu =  26923223: 17c =   179, 18c =  62267, 19c =    42897, 20c =   50951217, 21c =   0  ( 65.47%)
 Band036:  ng =  38536298, nu =  13176180: 17c =    91, 18c =  28689, 19c =    20371, 20c =   25310967, 21c =   0  ( 65.81%)
 Band037:  ng =  76146967, nu =  23300968: 17c =   216, 18c =  67880, 19c =    46423, 20c =   52731480, 21c =   0  ( 69.40%)
 Band038:  ng =  74505665, nu =  22430824: 17c =   250, 18c =  70557, 19c =    50509, 20c =   51953525, 21c =   0  ( 69.89%)
 Band039:  ng =  74154564, nu =  26857285: 17c =   175, 18c =  52462, 19c =    37886, 20c =   47206756, 21c =   0  ( 63.78%)
 Band040:  ng =  72171447, nu =  17081609: 17c =   353, 18c =  97556, 19c =    57828, 20c =   54934101, 21c =   0  ( 76.33%)
 Band041:  ng =  36053455, nu =   9586525: 17c =   161, 18c =  45091, 19c =    25942, 20c =   26395736, 21c =   0  ( 73.41%)
 Band042:  ng =  70552290, nu =  24561151: 17c =   147, 18c =  47932, 19c =    33222, 20c =   45909838, 21c =   0  ( 65.19%)
 Band043:  ng =  69437575, nu =  21326909: 17c =   237, 18c =  65875, 19c =    44669, 20c =   47999885, 21c =   0  ( 69.29%)
 Band044:  ng =  67978951, nu =  22759980: 17c =   135, 18c =  52864, 19c =    45916, 20c =   45120056, 21c =   0  ( 66.52%)
 Band045:  ng =  33904021, nu =  14767056: 17c =    38, 18c =  14862, 19c =    14144, 20c =   19107921, 21c =   0  ( 56.44%)
 Band046:  ng =  66337407, nu =  24184939: 17c =   116, 18c =  43277, 19c =    36471, 20c =   42072604, 21c =   0  ( 63.54%)
 Band047:  ng =  65880161, nu =  21831544: 17c =   147, 18c =  52855, 19c =    38797, 20c =   43956818, 21c =   0  ( 66.86%)
 Band048:  ng =  64996381, nu =  30716412: 17c =    66, 18c =  23113, 19c =    21639, 20c =   34235151, 21c =   0  ( 52.74%)
 Band049:  ng =  63898062, nu =  21707065: 17c =   163, 18c =  48329, 19c =    36152, 20c =   42106353, 21c =   0  ( 66.03%)
 Band050:  ng =  62192220, nu =  13477465: 17c =   363, 18c =  95689, 19c =    56828, 20c =   48561875, 21c =   0  ( 78.33%)
 Band051:  ng =  61691475, nu =  18628761: 17c =   181, 18c =  59192, 19c =    38439, 20c =   42964902, 21c =   0  ( 69.80%)
 Band052:  ng =  60192385, nu =  16789851: 17c =   208, 18c =  65227, 19c =    43050, 20c =   43294049, 21c =   0  ( 72.11%)
 Band053:  ng =  29966384, nu =   7108519: 17c =   159, 18c =  41850, 19c =    24570, 20c =   22791286, 21c =   0  ( 76.28%)
 Band054:  ng =  29734495, nu =  12875684: 17c =    41, 18c =  12848, 19c =    10277, 20c =   16835645, 21c =   0  ( 56.70%)
 Band055:  ng =  58731513, nu =  16660759: 17c =   228, 18c =  62905, 19c =    41102, 20c =   41966519, 21c =   0  ( 71.63%)
 Band056:  ng =  57263818, nu =  13406217: 17c =   370, 18c =  85461, 19c =    53422, 20c =   43718348, 21c =   0  ( 76.59%)
 Band057:  ng =  57033275, nu =  18036416: 17c =   182, 18c =  53549, 19c =    35162, 20c =   38907966, 21c =   0  ( 68.38%)
 Band058:  ng =  55394556, nu =  16714276: 17c =   153, 18c =  49588, 19c =    32931, 20c =   38597608, 21c =   0  ( 69.83%)
 Band059:  ng =  55022930, nu =  17901187: 17c =   143, 18c =  43532, 19c =    29778, 20c =   37048290, 21c =   0  ( 67.47%)
 Band060:  ng =  54018514, nu =  14216222: 17c =   243, 18c =  71204, 19c =    43282, 20c =   39687563, 21c =   0  ( 73.68%)
 Band061:  ng =  52964870, nu =  12168156: 17c =   337, 18c =  80560, 19c =    45911, 20c =   40669906, 21c =   0  ( 77.03%)
 Band062:  ng =  52242492, nu =  16458380: 17c =   139, 18c =  49232, 19c =    32406, 20c =   35702335, 21c =   0  ( 68.50%)
 Band063:  ng =  51245000, nu =  14630627: 17c =   204, 18c =  53700, 19c =    32321, 20c =   36528148, 21c =   0  ( 71.45%)
 Band064:  ng =  50540742, nu =  13739270: 17c =   206, 18c =  54741, 19c =    34041, 20c =   36712484, 21c =   0  ( 72.82%)
 Band065:  ng =  49644127, nu =  10593638: 17c =   324, 18c =  82652, 19c =    47138, 20c =   38920375, 21c =   0  ( 78.66%)
 Band066:  ng =  49190978, nu =  15393779: 17c =   121, 18c =  49150, 19c =    34807, 20c =   33713121, 21c =   0  ( 68.71%)
 Band067:  ng =  24077300, nu =   9985532: 17c =    41, 18c =  11824, 19c =    11396, 20c =   14068507, 21c =   0  ( 58.53%)
 Band068:  ng =  47978806, nu =  11458992: 17c =   278, 18c =  69164, 19c =    41225, 20c =   36409147, 21c =   0  ( 76.12%)
 Band069:  ng =  47059527, nu =  14180852: 17c =   137, 18c =  42046, 19c =    29664, 20c =   32806828, 21c =   0  ( 69.87%)
 Band070:  ng =  46231581, nu =  10722694: 17c =   254, 18c =  69020, 19c =    40961, 20c =   35398652, 21c =   0  ( 76.81%)
 Band071:  ng =  22715795, nu =   7342308: 17c =    79, 18c =  20862, 19c =    14884, 20c =   15337662, 21c =   0  ( 67.68%)
 Band072:  ng =  44778204, nu =  17961505: 17c =    87, 18c =  28542, 19c =    24129, 20c =   26763941, 21c =   0  ( 59.89%)
 Band073:  ng =  44053469, nu =  12061573: 17c =   189, 18c =  48835, 19c =    29657, 20c =   31913215, 21c =   0  ( 72.62%)
 Band074:  ng =  43401907, nu =  17754443: 17c =    54, 18c =  20277, 19c =    16502, 20c =   25610631, 21c =   0  ( 59.09%)
 Band075:  ng =  21398806, nu =   7037937: 17c =    46, 18c =  16393, 19c =    12447, 20c =   14331983, 21c =   0  ( 67.11%)
 Band076:  ng =  42061440, nu =  10927494: 17c =   171, 18c =  52207, 19c =    35488, 20c =   31046080, 21c =   0  ( 74.02%)
 Band077:  ng =  41316125, nu =  10937356: 17c =   191, 18c =  52477, 19c =    33560, 20c =   30292541, 21c =   0  ( 73.53%)
 Band078:  ng =  40571245, nu =  11040368: 17c =   143, 18c =  45546, 19c =    30796, 20c =   29454392, 21c =   0  ( 72.79%)
 Band079:  ng =  40282447, nu =   9989268: 17c =   178, 18c =  54418, 19c =    33113, 20c =   30205470, 21c =   0  ( 75.20%)
 Band080:  ng =  39233218, nu =  10980518: 17c =   182, 18c =  47247, 19c =    28928, 20c =   28176343, 21c =   0  ( 72.01%)
 Band081:  ng =  38522319, nu =  11551186: 17c =   176, 18c =  41217, 19c =    27650, 20c =   26902090, 21c =   0  ( 70.01%)
 Band082:  ng =  37881913, nu =  12029830: 17c =   126, 18c =  35286, 19c =    22656, 20c =   25794015, 21c =   0  ( 68.24%)
 Band083:  ng =  37460193, nu =  17607860: 17c =    38, 18c =  12134, 19c =    11969, 20c =   19828192, 21c =   0  ( 53.00%)
 Band084:  ng =  18460204, nu =   6976195: 17c =    28, 18c =  10939, 19c =     8732, 20c =   11464310, 21c =   0  ( 62.21%)
 Band085:  ng =  36127803, nu =   7673648: 17c =   265, 18c =  62459, 19c =    35246, 20c =   28356185, 21c =   0  ( 78.76%)
 Band086:  ng =  35584769, nu =   9060910: 17c =   203, 18c =  47824, 19c =    28518, 20c =   26447314, 21c =   0  ( 74.54%)
 Band087:  ng =  34821531, nu =   9577614: 17c =   132, 18c =  35140, 19c =    22804, 20c =   25185841, 21c =   0  ( 72.50%)
 Band088:  ng =  34334716, nu =   9476568: 17c =   109, 18c =  33660, 19c =    22051, 20c =   24802328, 21c =   0  ( 72.40%)
 Band089:  ng =  33769162, nu =   7122882: 17c =   239, 18c =  59802, 19c =    31827, 20c =   26554412, 21c =   0  ( 78.91%)
 Band090:  ng =  33174401, nu =   9538533: 17c =   118, 18c =  35445, 19c =    23201, 20c =   23577104, 21c =   0  ( 71.25%)
 Band091:  ng =  32520037, nu =   9201604: 17c =   113, 18c =  33322, 19c =    20488, 20c =   23264510, 21c =   0  ( 71.70%)
 Band092:  ng =  31945541, nu =   9417624: 17c =   102, 18c =  29236, 19c =    19346, 20c =   22479233, 21c =   0  ( 70.52%)
 Band093:  ng =  31221072, nu =  11968762: 17c =    55, 18c =  19952, 19c =    16955, 20c =   19215348, 21c =   0  ( 61.66%)
 Band094:  ng =  30579410, nu =   9204092: 17c =    77, 18c =  24076, 19c =    16954, 20c =   21334211, 21c =   0  ( 69.90%)
 Band095:  ng =  29977732, nu =   8614188: 17c =    99, 18c =  30040, 19c =    19726, 20c =   21313679, 21c =   0  ( 71.26%)
 Band096:  ng =  29390061, nu =   7051169: 17c =   179, 18c =  39062, 19c =    23033, 20c =   22276618, 21c =   0  ( 76.01%)
 Band097:  ng =  14518368, nu =   4347679: 17c =    33, 18c =  11778, 19c =     7703, 20c =   10151175, 21c =   0  ( 70.05%)
 Band098:  ng =  14372444, nu =   4327664: 17c =    36, 18c =  11745, 19c =     7647, 20c =   10025352, 21c =   0  ( 69.89%)
 Band099:  ng =  28268021, nu =   6866168: 17c =   138, 18c =  38431, 19c =    23459, 20c =   21339825, 21c =   0  ( 75.71%)
 Band100:  ng =  27849953, nu =  11813461: 17c =    47, 18c =  12257, 19c =    10767, 20c =   16013421, 21c =   0  ( 57.58%)
 Band101:  ng =  13768854, nu =   5721148: 17c =    20, 18c =   5612, 19c =     4580, 20c =    8037494, 21c =   0  ( 58.45%)
 Band102:  ng =  26929453, nu =   7514121: 17c =    77, 18c =  28580, 19c =    16436, 20c =   19370239, 21c =   0  ( 72.10%)
 Band103:  ng =  26382806, nu =   6455660: 17c =   102, 18c =  32645, 19c =    19693, 20c =   19874706, 21c =   0  ( 75.53%)
 Band104:  ng =   4359314, nu =   1834096: 17c =     5, 18c =   1814, 19c =     1452, 20c =    2521947, 21c =   0  ( 57.93%)
 Band105:  ng =  25997296, nu =  11631797: 17c =    17, 18c =   8549, 19c =     7423, 20c =   14349510, 21c =   0  ( 55.26%)
 Band106:  ng =  25467197, nu =   5479531: 17c =   158, 18c =  39498, 19c =    23193, 20c =   19924817, 21c =   0  ( 78.48%)
 Band107:  ng =  24888528, nu =   4160639: 17c =   212, 18c =  52455, 19c =    27644, 20c =   20647578, 21c =   0  ( 83.28%)
 Band108:  ng =  24423300, nu =   5997913: 17c =   115, 18c =  29131, 19c =    18855, 20c =   18377286, 21c =   0  ( 75.44%)
 Band109:  ng =  23988326, nu =   7541985: 17c =    77, 18c =  19762, 19c =    13709, 20c =   16412793, 21c =   0  ( 68.56%)
 Band110:  ng =  23541927, nu =   5665607: 17c =   101, 18c =  29298, 19c =    18564, 20c =   17828357, 21c =   0  ( 75.93%)
 Band111:  ng =  23070530, nu =   5223847: 17c =   119, 18c =  36160, 19c =    22454, 20c =   17787950, 21c =   0  ( 77.36%)
 Band112:  ng =  22609142, nu =   5499742: 17c =    89, 18c =  27613, 19c =    20277, 20c =   17061421, 21c =   0  ( 75.67%)
 Band113:  ng =  22100458, nu =   4862317: 17c =   135, 18c =  33013, 19c =    19772, 20c =   17185221, 21c =   0  ( 78.00%)
 Band114:  ng =  10879514, nu =   2808467: 17c =    54, 18c =  12599, 19c =     8263, 20c =    8050131, 21c =   0  ( 74.19%)
 Band115:  ng =  21378062, nu =   6386478: 17c =    70, 18c =  18367, 19c =    13586, 20c =   14959561, 21c =   0  ( 70.13%)
 Band116:  ng =  20985174, nu =   7066412: 17c =    65, 18c =  16892, 19c =    12493, 20c =   13889312, 21c =   0  ( 66.33%)
 Band117:  ng =  20674972, nu =   3394564: 17c =   219, 18c =  50322, 19c =    25867, 20c =   17204000, 21c =   0  ( 83.58%)
 Band118:  ng =  20107116, nu =   2928956: 17c =   299, 18c =  51173, 19c =    25404, 20c =   17101284, 21c =   0  ( 85.43%)
 Band119:  ng =  19854606, nu =   5589688: 17c =    68, 18c =  19689, 19c =    12056, 20c =   14233105, 21c =   0  ( 71.85%)
 Band120:  ng =   9732970, nu =   1381857: 17c =   142, 18c =  27636, 19c =    12832, 20c =    8310503, 21c =   0  ( 85.80%)
 Band121:  ng =  19084488, nu =   2856242: 17c =   250, 18c =  47570, 19c =    23462, 20c =   16156964, 21c =   0  ( 85.03%)
 Band122:  ng =   9491325, nu =   3405698: 17c =    21, 18c =   6554, 19c =     4077, 20c =    6074975, 21c =   0  ( 64.12%)
 Band123:  ng =  18532281, nu =   3881371: 17c =    98, 18c =  29451, 19c =    18235, 20c =   14603126, 21c =   0  ( 79.06%)
 Band124:  ng =   9142485, nu =   2411399: 17c =    28, 18c =  10724, 19c =     7331, 20c =    6713003, 21c =   0  ( 73.62%)
 Band125:  ng =  18075269, nu =   2918719: 17c =   192, 18c =  42177, 19c =    22527, 20c =   15091654, 21c =   0  ( 83.85%)
 Band126:  ng =  17675306, nu =   3599983: 17c =   113, 18c =  31097, 19c =    17620, 20c =   14026493, 21c =   0  ( 79.63%)
 Band127:  ng =  17545752, nu =   4279498: 17c =    75, 18c =  22290, 19c =    14448, 20c =   13229441, 21c =   0  ( 75.61%)
 Band128:  ng =  16990098, nu =   2974922: 17c =   110, 18c =  28982, 19c =    16390, 20c =   13969694, 21c =   0  ( 82.49%)
 Band129:  ng =   8369473, nu =   2162705: 17c =    27, 18c =   8555, 19c =     5017, 20c =    6193169, 21c =   0  ( 74.16%)
 Band130:  ng =  16406705, nu =   2403431: 17c =   196, 18c =  42005, 19c =    20486, 20c =   13940587, 21c =   0  ( 85.35%)
 Band131:  ng =  16189996, nu =   3685462: 17c =    61, 18c =  21520, 19c =    12209, 20c =   12470744, 21c =   0  ( 77.24%)
 Band132:  ng =  15791769, nu =   4137405: 17c =    66, 18c =  17315, 19c =    10455, 20c =   11626528, 21c =   0  ( 73.80%)
 Band133:  ng =   2613345, nu =   1067740: 17c =     1, 18c =    929, 19c =      772, 20c =    1543903, 21c =   0  ( 59.14%)
 Band134:  ng =  15362664, nu =   2305567: 17c =   168, 18c =  36442, 19c =    18824, 20c =   13001663, 21c =   0  ( 84.99%)
 Band135:  ng =  15272476, nu =   3753201: 17c =    73, 18c =  18933, 19c =    11665, 20c =   11488604, 21c =   0  ( 75.43%)
 Band136:  ng =  14918036, nu =   3535258: 17c =    67, 18c =  20468, 19c =    12856, 20c =   11349387, 21c =   0  ( 76.30%)
 Band137:  ng =   7254450, nu =   1906123: 17c =    21, 18c =   7302, 19c =     5136, 20c =    5335868, 21c =   0  ( 73.72%)
 Band138:  ng =  14383075, nu =   2517651: 17c =   150, 18c =  31632, 19c =    16034, 20c =   11817608, 21c =   0  ( 82.50%)
 Band139:  ng =   7011714, nu =   1018919: 17c =    71, 18c =  17713, 19c =     8700, 20c =    5966311, 21c =   0  ( 85.47%)
 Band140:  ng =  13738161, nu =   4038125: 17c =    39, 18c =  13224, 19c =    10820, 20c =    9675953, 21c =   0  ( 70.61%)
 Band141:  ng =  13445152, nu =   2223514: 17c =    95, 18c =  28162, 19c =    16427, 20c =   11176954, 21c =   0  ( 83.46%)
 Band142:  ng =   6593805, nu =    979629: 17c =    64, 18c =  15846, 19c =     8006, 20c =    5590260, 21c =   0  ( 85.14%)
 Band143:  ng =  12918117, nu =   1751255: 17c =   124, 18c =  32140, 19c =    17408, 20c =   11117190, 21c =   0  ( 86.44%)
 Band144:  ng =   6403269, nu =   1070061: 17c =    44, 18c =  12201, 19c =     7283, 20c =    5313680, 21c =   0  ( 83.29%)
 Band145:  ng =  12568136, nu =   1446343: 17c =   176, 18c =  34598, 19c =    18272, 20c =   11068747, 21c =   0  ( 88.49%)
 Band146:  ng =  12354720, nu =   1735745: 17c =   109, 18c =  28063, 19c =    14905, 20c =   10575898, 21c =   0  ( 85.95%)
 Band147:  ng =  12036469, nu =   1859672: 17c =    95, 18c =  25274, 19c =    13990, 20c =   10137438, 21c =   0  ( 84.55%)
 Band148:  ng =   5931073, nu =   1333507: 17c =    25, 18c =   7263, 19c =     4511, 20c =    4585767, 21c =   0  ( 77.52%)
 Band149:  ng =   5949060, nu =   1299835: 17c =    29, 18c =   8228, 19c =     5316, 20c =    4635652, 21c =   0  ( 78.15%)
 Band150:  ng =  11577852, nu =   1788877: 17c =    83, 18c =  24566, 19c =    14919, 20c =    9749407, 21c =   0  ( 84.55%)
 Band151:  ng =  11435633, nu =   2312356: 17c =    56, 18c =  18050, 19c =    11233, 20c =    9093938, 21c =   0  ( 79.78%)
 Band152:  ng =  11155974, nu =   3001624: 17c =    42, 18c =  12487, 19c =     8274, 20c =    8133547, 21c =   0  ( 73.09%)
 Band153:  ng =  10671486, nu =   1254930: 17c =   154, 18c =  28899, 19c =    15169, 20c =    9372334, 21c =   0  ( 88.24%)
 Band154:  ng =  10525735, nu =   1227380: 17c =   114, 18c =  28301, 19c =    14924, 20c =    9255016, 21c =   0  ( 88.34%)
 Band155:  ng =  10188634, nu =    942832: 17c =   164, 18c =  36458, 19c =    17538, 20c =    9191642, 21c =   0  ( 90.75%)
 Band156:  ng =  10059617, nu =   1445122: 17c =    86, 18c =  21708, 19c =    12132, 20c =    8580569, 21c =   0  ( 85.63%)
 Band157:  ng =   9805813, nu =   1443212: 17c =   106, 18c =  23908, 19c =    12083, 20c =    8326504, 21c =   0  ( 85.28%)
 Band158:  ng =   9629320, nu =   1572017: 17c =    55, 18c =  18675, 19c =    11714, 20c =    8026859, 21c =   0  ( 83.67%)
 Band159:  ng =   9490222, nu =   1393557: 17c =    92, 18c =  21759, 19c =    11939, 20c =    8062875, 21c =   0  ( 85.32%)
 Band160:  ng =   9280124, nu =   1919410: 17c =    30, 18c =  13302, 19c =     8081, 20c =    7339301, 21c =   0  ( 79.32%)
 Band161:  ng =   8844112, nu =   1309799: 17c =    70, 18c =  20131, 19c =    10804, 20c =    7503308, 21c =   0  ( 85.19%)
 Band162:  ng =   8628099, nu =    899066: 17c =   110, 18c =  27917, 19c =    14081, 20c =    7686925, 21c =   0  ( 89.58%)
 Band163:  ng =   8429593, nu =   1249705: 17c =    85, 18c =  20299, 19c =    10582, 20c =    7148922, 21c =   0  ( 85.17%)
 Band164:  ng =   8227144, nu =   1183135: 17c =    56, 18c =  17823, 19c =     9637, 20c =    7016493, 21c =   0  ( 85.62%)
 Band165:  ng =   7998287, nu =    753578: 17c =   140, 18c =  29975, 19c =    14642, 20c =    7199952, 21c =   0  ( 90.58%)
 Band166:  ng =   7813413, nu =   1030656: 17c =    79, 18c =  19049, 19c =     9861, 20c =    6753768, 21c =   0  ( 86.81%)
 Band167:  ng =   3839149, nu =    591145: 17c =    47, 18c =   9076, 19c =     5283, 20c =    3233598, 21c =   0  ( 84.60%)
 Band168:  ng =   7548052, nu =    704707: 17c =   171, 18c =  31356, 19c =    13902, 20c =    6797916, 21c =   0  ( 90.66%)
 Band169:  ng =   7349287, nu =    726565: 17c =   154, 18c =  26699, 19c =    12833, 20c =    6583036, 21c =   0  ( 90.11%)
 Band170:  ng =   7146807, nu =    685295: 17c =    98, 18c =  26884, 19c =    12807, 20c =    6421723, 21c =   0  ( 90.41%)
 Band171:  ng =   6993422, nu =   1577879: 17c =    44, 18c =  10729, 19c =     6552, 20c =    5398218, 21c =   0  ( 77.44%)
 Band172:  ng =   6828801, nu =   1034657: 17c =    61, 18c =  15570, 19c =     8025, 20c =    5770488, 21c =   0  ( 84.85%)
 Band173:  ng =   6674911, nu =    895972: 17c =    67, 18c =  16074, 19c =     8536, 20c =    5754262, 21c =   0  ( 86.58%)
 Band174:  ng =   6476248, nu =   1227200: 17c =    37, 18c =  10712, 19c =     6378, 20c =    5231921, 21c =   0  ( 81.05%)
 Band175:  ng =   3166465, nu =    501237: 17c =    33, 18c =   7150, 19c =     4138, 20c =    2653907, 21c =   0  ( 84.17%)
 Band176:  ng =   6205963, nu =    634350: 17c =    98, 18c =  22217, 19c =    10985, 20c =    5538313, 21c =   0  ( 89.78%)
 Band177:  ng =   6040631, nu =    600905: 17c =   115, 18c =  22861, 19c =    10781, 20c =    5405969, 21c =   0  ( 90.05%)
 Band178:  ng =   5882934, nu =    721010: 17c =    80, 18c =  18347, 19c =     8907, 20c =    5134590, 21c =   0  ( 87.74%)
 Band179:  ng =   5812748, nu =    617700: 17c =    88, 18c =  20822, 19c =    10002, 20c =    5164136, 21c =   0  ( 89.37%)
 Band180:  ng =   5615082, nu =    741885: 17c =    66, 18c =  16046, 19c =     8199, 20c =    4848886, 21c =   0  ( 86.79%)
 Band181:  ng =   5461387, nu =    740497: 17c =    62, 18c =  14942, 19c =     7375, 20c =    4698511, 21c =   0  ( 86.44%)
 Band182:  ng =   5367414, nu =   1078090: 17c =    35, 18c =   9356, 19c =     5485, 20c =    4274448, 21c =   0  ( 79.91%)
 Band183:  ng =   5222068, nu =   1698693: 17c =    12, 18c =   4014, 19c =     2920, 20c =    3516429, 21c =   0  ( 67.47%)
 Band184:  ng =   5072949, nu =    639546: 17c =    84, 18c =  15935, 19c =     7436, 20c =    4409948, 21c =   0  ( 87.39%)
 Band185:  ng =   4918277, nu =    481652: 17c =   110, 18c =  18796, 19c =     9282, 20c =    4408437, 21c =   0  ( 90.21%)
 Band186:  ng =   4778878, nu =    698167: 17c =    47, 18c =  11247, 19c =     6142, 20c =    4063275, 21c =   0  ( 85.39%)
 Band187:  ng =   4641003, nu =   1035177: 17c =    38, 18c =   8248, 19c =     5018, 20c =    3592522, 21c =   0  ( 77.69%)
 Band188:  ng =   4539624, nu =    844775: 17c =    34, 18c =   8088, 19c =     4736, 20c =    3681991, 21c =   0  ( 81.39%)
 Band189:  ng =   4407284, nu =    829510: 17c =    28, 18c =   7575, 19c =     4669, 20c =    3565502, 21c =   0  ( 81.18%)
 Band190:  ng =   2186822, nu =         0: 17c =    19, 18c =   4465, 19c =     2462, 20c =    2179876, 21c =   0  (100.00%)
 Band191:  ng =   4220821, nu =    758838: 17c =    30, 18c =   8018, 19c =     4449, 20c =    3449486, 21c =   0  ( 82.02%)
 Band192:  ng =   4158097, nu =    920505: 17c =    21, 18c =   6838, 19c =     3894, 20c =    3226839, 21c =   0  ( 77.86%)
 Band193:  ng =   4070158, nu =    877196: 17c =    17, 18c =   5934, 19c =     3520, 20c =    3183491, 21c =   0  ( 78.45%)
 Band194:  ng =   3857103, nu =    468202: 17c =    37, 18c =  10748, 19c =     5418, 20c =    3372698, 21c =   0  ( 87.86%)
 Band195:  ng =   3785628, nu =    691572: 17c =    19, 18c =   6942, 19c =     3716, 20c =    3083379, 21c =   0  ( 81.73%)
 Band196:  ng =   3693474, nu =    820446: 17c =    27, 18c =   6359, 19c =     3674, 20c =    2862968, 21c =   0  ( 77.79%)
 Band197:  ng =   3555681, nu =         0: 17c =    74, 18c =  12384, 19c =     5983, 20c =    3537240, 21c =   0  (100.00%)
 Band198:  ng =   3453089, nu =    452973: 17c =    32, 18c =  10427, 19c =     5858, 20c =    2983799, 21c =   0  ( 86.88%)
 Band199:  ng =   3345667, nu =         0: 17c =    80, 18c =  14888, 19c =     6867, 20c =    3323832, 21c =   0  (100.00%)
 Band200:  ng =   3252227, nu =         0: 17c =    66, 18c =  14067, 19c =     6730, 20c =    3231364, 21c =   0  (100.00%)
 Band201:  ng =   3165254, nu =         0: 17c =    82, 18c =  14851, 19c =     6724, 20c =    3143597, 21c =   0  (100.00%)
 Band202:  ng =   3064062, nu =         0: 17c =    28, 18c =   8584, 19c =     4642, 20c =    3050808, 21c =   0  (100.00%)
 Band203:  ng =   2966309, nu =         0: 17c =    34, 18c =   8568, 19c =     4369, 20c =    2953338, 21c =   0  (100.00%)
 Band204:  ng =   2932890, nu =         0: 17c =    33, 18c =   8878, 19c =     4741, 20c =    2919238, 21c =   0  (100.00%)
 Band205:  ng =   2841380, nu =         0: 17c =    36, 18c =   8034, 19c =     3907, 20c =    2829403, 21c =   0  (100.00%)
 Band206:  ng =   2701985, nu =         0: 17c =    70, 18c =  12909, 19c =     5656, 20c =    2683350, 21c =   0  (100.00%)
 Band207:  ng =   2628788, nu =         0: 17c =    71, 18c =  11689, 19c =     5289, 20c =    2611739, 21c =   0  (100.00%)
 Band208:  ng =   2532198, nu =         0: 17c =    22, 18c =   6706, 19c =     3639, 20c =    2521831, 21c =   0  (100.00%)
 Band209:  ng =   2443960, nu =         0: 17c =    43, 18c =  11112, 19c =     5189, 20c =    2427616, 21c =   0  (100.00%)
 Band210:  ng =   1243959, nu =         0: 17c =    22, 18c =   4816, 19c =     2149, 20c =    1236972, 21c =   0  (100.00%)
 Band211:  ng =   2317171, nu =         0: 17c =    54, 18c =  11325, 19c =     5077, 20c =    2300715, 21c =   0  (100.00%)
 Band212:  ng =   2357854, nu =         0: 17c =    52, 18c =   9262, 19c =     4250, 20c =    2344290, 21c =   0  (100.00%)
 Band213:  ng =   1137589, nu =         0: 17c =     5, 18c =   1782, 19c =     1143, 20c =    1134659, 21c =   0  (100.00%)
 Band214:  ng =   1083228, nu =         0: 17c =    11, 18c =   2052, 19c =     1314, 20c =    1079851, 21c =   0  (100.00%)
 Band215:  ng =   2183311, nu =         0: 17c =    45, 18c =   8682, 19c =     4178, 20c =    2170406, 21c =   0  (100.00%)
 Band216:  ng =   2244753, nu =         0: 17c =    38, 18c =   7660, 19c =     3720, 20c =    2233335, 21c =   0  (100.00%)
 Band217:  ng =   2143677, nu =         0: 17c =    15, 18c =   3380, 19c =     2026, 20c =    2138256, 21c =   0  (100.00%)
 Band218:  ng =   2100798, nu =         0: 17c =     7, 18c =   2977, 19c =     2216, 20c =    2095598, 21c =   0  (100.00%)
 Band219:  ng =   1007465, nu =         0: 17c =     4, 18c =   1018, 19c =      977, 20c =    1005466, 21c =   0  (100.00%)
 Band220:  ng =   1970315, nu =         0: 17c =    11, 18c =   3153, 19c =     2257, 20c =    1964894, 21c =   0  (100.00%)
 Band221:  ng =   1841722, nu =         0: 17c =    14, 18c =   4258, 19c =     2517, 20c =    1834933, 21c =   0  (100.00%)
 Band222:  ng =   1873099, nu =         0: 17c =    17, 18c =   3838, 19c =     2405, 20c =    1866839, 21c =   0  (100.00%)
 Band223:  ng =   1772301, nu =         0: 17c =    12, 18c =   3023, 19c =     2146, 20c =    1767120, 21c =   0  (100.00%)
 Band224:  ng =    347777, nu =         0: 17c =     0, 18c =    138, 19c =      220, 20c =     347417, 21c =   2  (100.00%)
 Band225:  ng =   1968442, nu =         0: 17c =     6, 18c =   2158, 19c =     1696, 20c =    1964582, 21c =   0  (100.00%)
 Band226:  ng =   1677704, nu =         0: 17c =     9, 18c =   2720, 19c =     1838, 20c =    1673137, 21c =   0  (100.00%)
 Band227:  ng =   1521001, nu =         0: 17c =    17, 18c =   3905, 19c =     2124, 20c =    1514955, 21c =   0  (100.00%)
 Band228:  ng =   1498734, nu =         0: 17c =    11, 18c =   3034, 19c =     1915, 20c =    1493774, 21c =   0  (100.00%)
 Band229:  ng =   1515366, nu =         0: 17c =    22, 18c =   3889, 19c =     2024, 20c =    1509431, 21c =   0  (100.00%)
 Band230:  ng =   1457098, nu =         0: 17c =    16, 18c =   2223, 19c =     1448, 20c =    1453411, 21c =   0  (100.00%)
 Band231:  ng =   1331185, nu =         0: 17c =     8, 18c =   4160, 19c =     2181, 20c =    1324836, 21c =   0  (100.00%)
 Band232:  ng =   1279569, nu =         0: 17c =     2, 18c =   2467, 19c =     1374, 20c =    1275726, 21c =   0  (100.00%)
 Band233:  ng =   1262013, nu =         0: 17c =     9, 18c =   2352, 19c =     1483, 20c =    1258169, 21c =   0  (100.00%)
 Band234:  ng =   1218744, nu =         0: 17c =    23, 18c =   4053, 19c =     2162, 20c =    1212506, 21c =   0  (100.00%)
 Band235:  ng =    386642, nu =         0: 17c =     8, 18c =   1529, 19c =      735, 20c =     384370, 21c =   0  (100.00%)
 Band236:  ng =   1182963, nu =         0: 17c =    22, 18c =   5407, 19c =     2549, 20c =    1174985, 21c =   0  (100.00%)
 Band237:  ng =    570172, nu =         0: 17c =     1, 18c =    216, 19c =      405, 20c =     569550, 21c =   0  (100.00%)
 Band238:  ng =   1111083, nu =         0: 17c =     2, 18c =   1517, 19c =     1351, 20c =    1108213, 21c =   0  (100.00%)
 Band239:  ng =   1076551, nu =         0: 17c =    13, 18c =   3012, 19c =     1591, 20c =    1071935, 21c =   0  (100.00%)
 Band240:  ng =    167032, nu =         0: 17c =     0, 18c =    117, 19c =      139, 20c =     166776, 21c =   0  (100.00%)
 Band241:  ng =    533940, nu =         0: 17c =     5, 18c =   1530, 19c =     1054, 20c =     531351, 21c =   0  (100.00%)
 Band242:  ng =   1048083, nu =         0: 17c =    15, 18c =   3771, 19c =     2133, 20c =    1042164, 21c =   0  (100.00%)
 Band243:  ng =    974591, nu =         0: 17c =    19, 18c =   4756, 19c =     2417, 20c =     967399, 21c =   0  (100.00%)
 Band244:  ng =    967788, nu =         0: 17c =    18, 18c =   4385, 19c =     2276, 20c =     961109, 21c =   0  (100.00%)
 Band245:  ng =    455310, nu =         0: 17c =     2, 18c =   1425, 19c =      754, 20c =     453129, 21c =   0  (100.00%)
 Band246:  ng =    915249, nu =         0: 17c =    12, 18c =   3249, 19c =     1832, 20c =     910156, 21c =   0  (100.00%)
 Band247:  ng =    500537, nu =         0: 17c =     4, 18c =   1101, 19c =      737, 20c =     498695, 21c =   0  (100.00%)
 Band248:  ng =    783336, nu =         0: 17c =    22, 18c =   5464, 19c =     2437, 20c =     775413, 21c =   0  (100.00%)
 Band249:  ng =    822496, nu =         0: 17c =    18, 18c =   4231, 19c =     2128, 20c =     816119, 21c =   0  (100.00%)
 Band250:  ng =   4118353, nu =         0: 17c =   102, 18c =  17397, 19c =     8384, 20c =    4092470, 21c =   0  (100.00%)
 Band260:  ng =   4942966, nu =         0: 17c =   141, 18c =  29358, 19c =    13339, 20c =    4900128, 21c =   0  (100.00%)
 Band270:  ng =   2374942, nu =         0: 17c =    80, 18c =  15562, 19c =     7117, 20c =    2352183, 21c =   0  (100.00%)
 Band280:  ng =   1443458, nu =         0: 17c =    42, 18c =   8338, 19c =     3867, 20c =    1431211, 21c =   0  (100.00%)
 Band290:  ng =   1584461, nu =         0: 17c =    63, 18c =  10999, 19c =     4815, 20c =    1568584, 21c =   0  (100.00%)
 Band300:  ng =   2097068, nu =         0: 17c =   105, 18c =  19476, 19c =     8094, 20c =    2069393, 21c =   0  (100.00%)


[Mathimagics]

72 hours gone, and stage 2 has found 267 million 20C puzzles (all with 668-pattern). With 5 workers, this is 17.8 million grids per worker/day. Hats off to blue for that! That's roughly 1/5 of the 1,365,506,043 candidates, so the completion date might be 13 August.

Interesting to note that NO new cases of "no 668 20C puzzle" have been found. Might blue's table above in fact be complete? We'll just have to wait and see ...

[Mathimagics]

For finding a 19C for a grid, it's faster to look first, for puzzles with >= 8 clues a band/stack.

Thanks blue for those timings. You anticipated my questions just as I was contemplating them ...

Guesstimating times for LCT-19 is more complicated than it was LCT-20.

Let's say BlueMagic has these 2 functions, Find19C-8 for finding 19C puzzles with 8 or more clues per band/stack, and Find19C-7 for finding {667} puzzles.

So, with X = price of a Find20C call, the price of 19C testing is probably going to be Find19C-8 ~= 5X, and Find19C-7 ~= 27X.

Reducing the pool size (grids that need to be tested with Find19C) will be crucial. So, the morphing workers will clearly have to do most of the heavy lifting. How they will actually perform in the 19C context is harder to predict, but I don't expect major degradation there - I do need to run some preliminary tests, however.

Cheers
MM

PS: blue, can you do some sampling and give estimates of the probability that a grid will (a) fail the 19C-8 test, (b) fail both tests?

PPS: LCT-20 is motoring through the unresolved grids, only 972,353,033 to go ...