The New Sudoku Players' Forum

[Hajime]

Here a Windoku, but without the 9 standard 3x3 boxes.

1: naked singles only, for paper&pencil solvers, symmetric puzzle:

Code: Select all

. . 2 5 . 7 4 . .
8 . . . 1 . . . 3
. . . 9 . 4 . . .
9 . 7 8 . 2 3 . 4
. . . 7 2 9 . . .
4 . 5 3 . 1 6 . 8
. . . 1 . 5 . . .
1 . . . 9 . . . 5
. . 9 6 . 3 5 . .

..25.74..8...1...3...9.4...9.78.23.4...729...4.53.16.8...1.5...1...9...5..96.35..


Only 4 extra constraints? No...
Read carefully https://www.sudokuwiki.org/Windoku_Strategy
There are 5 hidden constraints and you will need them.

2: medium, with some naked pairs, pointing/claiming and an XY-wing:

Code: Select all

. 6 . 5 4 . . . .
. . . 3 . . . . .
7 . . . . 8 4 . .
6 9 . . . . . . .
5 . 3 . . . . . 2
3 . . 7 9 . . 6 .
. . . . . . 7 2 .
. . 1 . . 5 . 3 4
. . 8 . . . . 7 .

.6.54.......3.....7....84..69.......5.3.....23..79..6.......72...1..5.34..8....7.

3: hard, for the bits&bytes solvers

Code: Select all

3 6 . . 1 . . 7 .
. 8 . . . . . . .
. . . . 9 . . . .
7 5 3 . . . . . .
8 . 9 . . . . 6 .
. . . . . . 6 . 2
9 . 7 . . 2 1 . 3
. . . 2 . 8 . . 4
. . . 7 2 . 8 . .

36..1..7..8...........9....753......8.9....6.......6.29.7..21.3...2.8..4...72.8..

[creint]

A sudoku transformed to a windoku. A good test if your solver finds the same exclusions as the normal sudoku variant.

[Pat]

https://www.sudokuwiki.org/Windoku_Strategy
There are 5 hidden houses

yes

example (in your first puzzle):
(2) r6-8 -w34 \ r7
solves c7 2

that would rate 2.6?

[Hajime]

.... that would rate 2.6?

because of the hidden 2?
There is a solution path with naked singles only. So SER=2.3.

[Pat]

i used the 2.6 move

you reached "singles"
without such moves?
nice. i may have missed a "single"

could you please post the first 5 cells solved?

[Hajime]

i used the 2.6 move

you reached "singles"
without such moves?
nice. i may have missed a "single"

could you please post the first 5 cells solved?

The whole solution path:

Hidden Text: Show

Code: Select all

[1,1] r2c6=6 Naked Single
[1,2] r6c5=7 Naked Single
[1,3] r8c6=8 Naked Single
[1,4] r9c1=7 Naked Single
[1,5] r9c9=1 Naked Single
[2,6] r2c3=4 Naked Single
[2,7] r2c4=2 Naked Single
[2,8] r5c9=6 Naked Single
[2,9] r7c9=2 Naked Single
[2,10] r8c3=6 Naked Single
[2,11] r8c4=4 Naked Single
[3,12] r1c1=3 Naked Single
[3,13] r1c5=8 Naked Single
[3,14] r1c9=9 Naked Single
[3,15] r2c2=5 Naked Single
[3,16] r3c9=7 Naked Single
[3,17] r5c1=5 Naked Single
[3,18] r7c1=6 Naked Single
[3,19] r7c3=8 Naked Single
[3,20] r7c5=3 Naked Single
[3,21] r9c5=4 Naked Single
[4,22] r1c2=1 Naked Single
[4,23] r1c8=6 Naked Single
[4,24] r3c1=2 Naked Single
[4,25] r4c2=6 Naked Single
[4,26] r4c5=5 Naked Single
[4,27] r4c8=1 Naked Single
[4,28] r5c3=3 Naked Single
[4,29] r5c8=8 Naked Single
[4,30] r9c2=8 Naked Single
[4,31] r9c8=2 Naked Single
[5,32] r3c2=3 Naked Single
[5,33] r3c3=1 Naked Single
[5,34] r3c5=6 Naked Single
[5,35] r3c7=8 Naked Single
[5,36] r3c8=5 Naked Single
[5,37] r5c2=4 Naked Single
[5,38] r5c7=1 Naked Single
[5,39] r6c8=9 Naked Single
[5,40] r7c7=7 Naked Single
[5,41] r7c8=4 Naked Single
[5,42] r8c7=2 Naked Single
[5,43] r8c8=3 Naked Single
[6,44] r2c7=9 Naked Single
[6,45] r2c8=7 Naked Single
[6,46] r6c2=2 Naked Single
[6,47] r7c2=9 Naked Single
[6,48] r8c2=7 Naked Single


[Pat]

thanks!

r9c1=7
is indeed a "naked single" right from the start,
which i missed



my path used 2.6
with "hidden singles"
- easier for me
(not marking possibilities in each cell)



★ using the obscure houses,
i found a path using only "hidden singles" (1.5)!

r9 2
most-obscure-house 459,8,3,6

, r9 8,1,7

etc

[Hajime]

★ using the obscure houses,
can i find a path using only "hidden singles"???

Only hidden singles is not possible
because the last singles are all naked or last one in a house.

Yesterday I generated 100 puzzles of which 3 are listed above.
Here are all 100. With an estimated SER.
Except SER=0.1 only naked singles ; SER=0.2 is naked/hidden singles.

Hidden Text: Show

Code: Select all

#1/JS/B4
85..7......6.....19...2..6.7..25.81..9...17..53....1..3...94..71.5..9.....3...6..
955596669711172227711172227711172227955596669833384448833384448833384448955596669

================================================================================= Nr SER/Labour/Guesses : Clues/Empty-Candidates

6.75..........14..9..4....2..98....1....9..3..2..4.........35.9...7...1.14.2..8.. 1 0.2/19.0/0 :  24c/57 - 222
.6.54.......3.....7....84..69.......5.3.....23..79..6.......72...1..5.34..8....7. 2 4.1/43.3/0 :  24c/57 - 210
32.4.1.....47..56.6.19.2.4.4.6....7...9...726........3...84..1........59......... 3 5.4/178.9/0 :  26c/55 - 220
..5.29.1...6...953...8.7.3....1....7.6.4..8......41....2.79........3.6.8......... 4 5.4/105.4/0 :  24c/57 - 209
..4....32...769.......2.5..1.....6...2.8......7..8..1...2.16.89..........3..98.5. 5 5.4/66.2/0 :  24c/57 - 233
.16.2..5.8...416.3.....8....7......93..4..7..457..3.6...32.....7........52.....3. 6 5.5/94.8/0 :  26c/55 - 204
...3.....548.....7...9..5.....1..6.9..9.8.4..89.....6.........53....2.8...2.96.31 7 0.2/14.1/0 :  25c/56 - 218
...96.5...1.8...65..5..3..1....2.......478.124...5...7...3.2....9..3..5........4. 8 5.4/91.6/0 :  25c/56 - 215
..9..4.3..7........8..6...4..3.7...23.....8..4..9...8.8.1.53....5.....61..57..1.. 9 4.1/47.8/0 :  25c/56 - 208
..813.96......9...24.3....84.6..5....7....81662.......8.1...........45.2......... 10 5.6/55.3/0 :  24c/57 - 221
..4........56.1.4...3...621.....9...86...3.7.9...2.....9.7..8.5...1.6....7..4...9 11 0.2/13.8/0 :  25c/56 - 202
.2......1.........9.4..5.3.......29.6....8..9.3..1..4....8.........8..65376..4.5. 12 0.2/16.9/0 :  23c/58 - 231
....1...3145....6..7...39.6.6....128...5.....5....7.1.9.6...2....8......4..3..... 13 0.2/10.6/0 :  24c/57 - 215
..2....14...78......1.34..7..6513.8.....7....6.71..5.....4.2....9......2.....86.. 14 0.1/5.6/0 :  25c/56 - 203
.4...6..22..8.............5.....14.6...1..3.7..57..14.....93.2.....7..5..8..3.5.. 15 0.2/15.9/0 :  24c/57 - 218
.7.38.1....3....5.8..9..27.....98...329.....5..5............8.6.324.6.........6.1 16 5.4/91.4/0 :  25c/56 - 210
21....8....67.5.....5...4.6....4........72.9........3.3.26....9...32...76.9..7..1 17 5.5/134.2/0 :  25c/56 - 216
72.....5.94.8..2....72........1.6..85.9.4.........2..94.....8....6.23..1...4..... 18 5.4/91.9/0 :  24c/57 - 224
...7...45.6.....2..1.5....9..7..54..7.4..91..1...2........3.6.....2..974......... 19 0.2/12.9/0 :  23c/58 - 233
.......21.3.8..95......6......4..1..96....7327.........21....462.43.8...3.....6.. 20 0.2/12.4/0 :  25c/56 - 210
.7..4...1.....3..2..9.8.7....4.5......2.....81.....9.....7......5..6..3.93...56.. 21 0.2/21.1/0 :  22c/59 - 230
.386......6.9.45..5.....6....346.29...9.7..8......7......23..68.913.....61....... 22 4.2/30.0/0 :  27c/54 - 197
.....4....2..195.6..6142.........1..3..6.....9....3.1...2....8..9........4..7.261 23 5.4/48.6/0 :  24c/57 - 236
......97..3.7.6.5....9.84....2....35.46..23..18...........7.19.3..4........1..... 24 0.2/9.0/0 :  24c/57 - 217
........9.8...4..3..51.7.68.9........1.58.........54..3.14..72.5........7..21.9.. 25 5.4/104.0/0 :  25c/56 - 220
4.278.....5.86.79......4....96.1....3....6........5.8.9........1..4..368........2 26 0.2/14.8/0 :  24c/57 - 218
..1...9865.....1......6...7......6..9..4......1....4...369...1.....978...5.74..38 27 0.1/5.6/0 :  25c/56 - 218
9...87.2......3.1....2.....6.4.....1.4.5....2....21.....26987...5.......5..8..6.. 28 7.6/96.2/2 :  24c/57 - 225
.12................2.1...5...89.6.1..5......468..123..4.3.....8...53.4....7..41.. 29 0.2/19.7/0 :  25c/56 - 226
1...9......72...4..5.9.1.3......2..9.1...3.6..2....1..4......253....5.....4...8.3 30 5.4/197.1/0 :  24c/57 - 227
8..3.......41....9.38....1.....65.........7...1.....856.984..3....2.1......52.... 31 0.2/15.6/0 :  23c/58 - 229
..8....76..98..5...5..4......7...2.87..518...6...7.....2.4.9.8..75....2.......1.9 32 7.6/73.8/4 :  26c/55 - 206
46..9....9....87.25......6..8.7.4...7.......5..4....3..9.3..8....7....5.6...39... 33 5.4/172.0/0 :  24c/57 - 227
......93...3..8.....2.4....3.642...9.1......7....5..12....8.3....7......6.5.31... 34 0.2/15.0/0 :  23c/58 - 236
69....5.4..7..12...........4..1....3.7.528.1....49.17.8............4...5.2...96.. 35 0.2/12.3/0 :  25c/56 - 221
..6827......4............58......2....9..1.....1.9.8..8.....5....5..3461.2....6.3 36 0.1/5.8/0 :  23c/58 - 239
8..7........9....3.....8.....42..51.....7.3....9..5.342..46...5...8..4..53.....6. 37 0.2/14.1/0 :  24c/57 - 223
.....2.......69...1...8...7427......8..5..4....17..25...4..1.3..5..4..9..8......5 38 0.2/23.1/0 :  24c/57 - 223
...........92......3......75.....79.8.....56..6.9.....21..6..531..3..4..95671..4. 39 4.2/26.4/0 :  26c/55 - 206
..4...8..8.547.............6.8...7...27.....9..1..5..2.7...23........4..51.....36 40 0.2/17.0/0 :  23c/58 - 235
865..3.7...3.24.....9....8.9.......6...2....7.....5..17..3.........5.2.8..7....4. 41 7.6/129.3/2 :  23c/58 - 237
9..4.5...2.39..1....2...63..5.....9..61.4...2.3....2......56..71.9.........5..... 42 5.0/44.4/0 :  24c/57 - 223
.62..41........6..1..3...2...5.6..18........62..8..........1..5.2.78.5.4....49... 43 7.6/44.7/4 :  24c/57 - 233
6..4.2..8.8....2...4......6..6.231....1.37.......8....79....4..1.....97...3...65. 44 6.3/118.7/0 :  25c/56 - 208
.....72813.6.....89....3.7.71.4.....8...3..6...4..8.1...7..2..4...3..4.....5..... 45 5.1/54.1/0 :  25c/56 - 213
...1..38.....94.37.2...95............6..7....8..5....1..2..3..4..4...1.6.582..... 46 5.0/70.8/0 :  24c/57 - 222
.8....6....31..4......385..24..........45....8.....3..9..6...7....32.96..97.1.... 47 0.2/12.1/0 :  24c/57 - 218
3.4.......3.......42..61.9......24.7.......6.........4..1...87...68.491.97......8 48 5.4/108.6/0 :  24c/57 - 221
.3.4..8......3.51.6.9.54...98......1.9...32.8.7.9..1....1..........82...4.....67. 49 4.1/25.3/0 :  26c/55 - 206
.1.......491....5....2...3....8....9....8...1...7..4.6..2.1.58.2.3......9...76... 50 5.4/190.3/0 :  23c/58 - 227
2.7.....869...5........74..7...41.2.....5..1.8..........2...83..19.......6.37...4 51 5.4/169.0/0 :  24c/57 - 214
.........6..93.....4...3.....2.8.6.1...1..27.8..27.....8.......27436....1.369..4. 52 0.2/13.8/0 :  26c/55 - 212
......4.....4....5.31........9..82..12......92..59....6....19.....8.37..5.7....6. 53 5.4/139.6/0 :  23c/58 - 210
...9..435.2.4...7...9.....8.5.6........3..7.6....59....7..245........1..2.1...8.. 54 0.2/12.3/0 :  24c/57 - 216
........3.2..564...6...8...1.9....5.....6.......58....71....89...42.7.6..4....381 55 4.1/19.6/0 :  25c/56 - 215
..3...74.....23...139.....4.....8.1.7..1....5.67..49...1....3..94..5...3..45..... 56 5.5/147.8/0 :  26c/55 - 200
...79.1.....4.5....16..9...5.2.......8.1..92475....3....3.6.7.....2.4...8.......3 57 0.2/13.1/0 :  25c/56 - 199
.57.4....8..2.......9.7.5.2....3..4....387........4.61.2...........2.8749...6..3. 58 5.5/102.4/0 :  25c/56 - 208
8...4..5....751..3...9...........4....15..2...2.1.6....9..8.3.7..3.2..8.....9..1. 59 5.4/181.6/0 :  24c/57 - 218
.2.95...61.95.........35...7..8.21..........3........7..8.9.7..2.4.6.9...7.4..58. 60 3.0/22.1/0 :  26c/55 - 195
4.75...1.2..4..756...3..1......3..9..1...4.....4.25.......9......1.8.96.8.....6.. 61 7.6/142.9/2 :  25c/56 - 210
..8.21.........5.....5.4..759.6..8....273.9.........934....3....4..8..166.......8 62 7.6/68.4/2 :  25c/56 - 207
53..8.9......9....4.7.3.1.....6..4.2.5..48.172.1....8.......5........74.98....... 63 5.4/88.9/0 :  25c/56 - 220
...6......39.4.2.............6..4.57..2.63......3...1..7..5..4....4.5786....2..74 64 0.2/23.7/0 :  25c/56 - 225
6..7.................18...52..9...4.1.3..786.84.27.......85.4....1....3.....3..2. 65 0.2/13.1/0 :  24c/57 - 230
86..917.........2....5.....7....65.9..5....865....3....7.1..964..3...4...9..1.... 66 7.6/150.3/12 :  25c/56 - 212
.5.92.....7..8..2..2..5.......8.61..3.4..2.....3..4.8..4...13........75.63....5.. 67 0.2/13.9/0 :  25c/56 - 219
.....5..1.5...3...74......21....4.58..74.2.1....6..1...38...7......86......2..6.4 68 0.2/17.8/0 :  25c/56 - 210
5.....893...849..1.594......2..............74..4192..6..29......6.......8..5..3.2 69 0.2/18.2/0 :  26c/55 - 213
45.7.32....4982......3..6..5.1.....9.4.......9.7..8..42...............3.6.....95. 70 0.2/9.1/0 :  24c/57 - 224
....3.5..74......84.2..1.......9..8..5..1...9..4........12.8.67.3.6..9........24. 71 2.8/56.3/0 :  24c/57 - 215
1..8...65......4317.36..8...4......8....2.....9...7.....635...2.......4.8395...7. 72 5.4/226.5/0 :  26c/55 - 204
...8....5...52....8..6......1.....737.6.95.......1.82..3....147..........2....9.6 73 0.2/14.7/0 :  23c/58 - 228
..41......9...746.9.72..5....6......23.....5.....86.7...........5..64..28.2...9.. 74 0.2/27.3/0 :  24c/57 - 229
7.....3.5.3..41...21......7..........6..15.8......8...1.4.8.7.9.....39..3..9...7. 75 0.2/20.7/0 :  24c/57 - 232
41.....6.2..4..5..72...9.3............5..79..9.8...3..8..25......3..6......96..2. 76 5.0/38.9/0 :  24c/57 - 224
...1.....3....2.6....4....12.....7.975......8...6.9..5...9..63.....1.5...2..53... 77 0.2/21.6/0 :  23c/58 - 231
....436..7.1.85....5....4.25...12.....3....7....157.8..6......81.9......8.7...... 78 0.2/24.3/0 :  25c/56 - 221
...3.......6.85.7..4..73..69.8......1.....3.9..5.........4...1.......7482.1..8.5. 79 0.2/21.9/0 :  24c/57 - 227
...4....87.3...15.......9......8..7..6.7...89.......672.1...7..5.9......3.....2.. 80 0.2/19.1/0 :  22c/59 - 243
.7.....5..23.8.........9....4.5.7.....1.6..25.....45..8.7...1...6..4...3.5.298... 81 0.2/15.4/0 :  25c/56 - 206
..........4...2....36.19...9...3.......591......85.23..5.6...8..1....4.76....37.5 82 7.6/168.0/2 :  25c/56 - 205
...23....45....7.689..5......2.7......63.......7...531.1....9......4.875.7....2.. 83 5.0/52.7/0 :  25c/56 - 221
.5...29..4..891.....257.......7.......4...8..9.....2.....3496..8.......71.6..47.. 84 5.5/72.5/0 :  25c/56 - 212
9........64....2.....2.6.9...8754.1....5...48...1.....8.....9.....83..61.34...8.. 85 0.2/14.5/0 :  25c/56 - 220
..8...1..6..8....5.9...2.6..2..7..58........6.4...3......5.....4.2.3.9...614..32. 86 5.0/63.3/0 :  25c/56 - 213
42....5....7.1..3.23.....45....7.29...1......7.....3.....568...98.....6.8....9... 87 0.2/9.3/0 :  24c/57 - 213
.85....91...3..4.54..27..6..97...2.....6.4...9.6..8..2.........5....1..3.1....8.. 88 4.6/55.4/0 :  25c/56 - 205
913.........4.8..9381.7....69........4.....8..3....5.......1...1.....726..2..5.7. 89 5.0/129.5/0 :  24c/57 - 225
98....3......6....5....91.......7......45....43.2...5...7.84.127.6....9.269.....8 90 7.6/47.9/4 :  26c/55 - 197
...7132....3....7..4.9.8..36..1..............2.68...5......2..4..7...9.5.3.29..4. 91 7.6/82.3/20 :  25c/56 - 201
.7.8.463.....9..7..61.2.......9.8....4..85...8..4.6..7......4.3.....2.....2.....6 92 5.4/168.7/0 :  24c/57 - 222
9..3..8.4.....2.9..6.4...1....28..6.82....1..64.5......1.92...3....1..4.1...5.... 93 5.4/93.9/0 :  26c/55 - 206
17........5...9..1.63......7.48.3........6......13...........982..3...59..847.23. 94 0.2/20.1/0 :  25c/56 - 211
3.1..5......2....76..8..7....4.1...523......4..23...9.......271..7.6..5....9..3.. 95 4.2/26.3/0 :  25c/56 - 213
...8567....563...2.2...4..64........8......5......7.....9......7...45..317...3.2. 96 0.2/20.3/0 :  24c/57 - 229
7.8.91.2.....17...3...6284........54.9.5...8...6..4...12.4........87....8.1.....5 97 5.0/74.5/0 :  27c/54 - 200
..5...4..9...82...1.65..9.3............6..7.....8..51......7.38.1..3......1.46.92 98 0.2/17.7/0 :  25c/56 - 215
.....39.1...7.5.2.9.5.6.4...4....3...6.......37.6.....1......95.....4....5.2...69 99 0.2/17.2/0 :  24c/57 - 228
36..1..7..8...........9....753......8.9....6.......6.29.7..21.3...2.8..4...72.8.. 100 7.6/147.8/14 :  25c/56 - 214

[Pat]

(i edited the above
while you were writing)



★ using the obscure houses,
i found a path using only "hidden singles" (1.5)!

[Hajime]

SER

Code: Select all

1.0: Last value in block, row or column
1.2: Hidden Single in block
1.5: Hidden Single in row or column
1.7: Direct Pointing
1.9: Direct Claiming
2.0: Direct Hidden Pair
2.3: Naked Single


Is there a "last candidate in cell" in SER ? That is my "naked single", like r9c1=7 in picture of first puzzle.
unfortunately with value 2.3 (in stead of 1.0), much higher than a hidden single 1.2 (block) or 1.5 (row,col).
In SiSeSuSo is used SER=0.1 naked single in cell ; SER=0.2 is hidden single in row,col,box.
Because there are overwhelming count of naked/hidden singles in a puzzle and much less pointing/claiming of locked pairs/triples or other methods, and these are summarized to get the "labour" of a puzzle.

[Leren]

Isn't this variant just a transformed Sudoku ? See Blue's top post here .

If I understand it, just swap rows 1&4 and 6&9, and columns 1&4 and 6&9, solve as per a normal Sudoku with 9 boxes, and perform the row column swaps again for your Windoku Solo solution.

Code: Select all

1 1 1 2 2 2 3 3 3          5 4 4 4 5 6 6 6 5
1 1 1 2 2 2 3 3 3          2 1 1 1 2 3 3 3 2
1 1 1 2 2 2 3 3 3          2 1 1 1 2 3 3 3 2
4 4 4 5 5 5 6 6 6          2 1 1 1 2 3 3 3 2
4 4 4 5 5 5 6 6 6   <-->   5 4 4 4 5 6 6 6 5
4 4 4 5 5 5 6 6 6          8 7 7 7 8 9 9 9 8
7 7 7 8 8 8 9 9 9          8 7 7 7 8 9 9 9 8
7 7 7 8 8 8 9 9 9          8 7 7 7 8 9 9 9 8
7 7 7 8 8 8 9 9 9          5 4 4 4 5 6 6 6 5

Excerpt from the post showing the Windoku Solo houses on the right and the Sudoku Boxes on the left.

Leren

[Hajime]

I did not realize that. Yes indeed, the layouts are isomorph.

[Pat]

19 of 100
rated 5.4?

3 32.4.1.....47..56.6.19.2.4.4.6....7...9...726........3...84..1........59.........
4 ..5.29.1...6...953...8.7.3....1....7.6.4..8......41....2.79........3.6.8.........
5 ..4....32...769.......2.5..1.....6...2.8......7..8..1...2.16.89..........3..98.5.
8 ...96.5...1.8...65..5..3..1....2.......478.124...5...7...3.2....9..3..5........4.
16 .7.38.1....3....5.8..9..27.....98...329.....5..5............8.6.324.6.........6.1
18 72.....5.94.8..2....72........1.6..85.9.4.........2..94.....8....6.23..1...4.....
23 .....4....2..195.6..6142.........1..3..6.....9....3.1...2....8..9........4..7.261
25 ........9.8...4..3..51.7.68.9........1.58.........54..3.14..72.5........7..21.9..
30 1...9......72...4..5.9.1.3......2..9.1...3.6..2....1..4......253....5.....4...8.3
33 46..9....9....87.25......6..8.7.4...7.......5..4....3..9.3..8....7....5.6...39...
48 3.4.......3.......42..61.9......24.7.......6.........4..1...87...68.491.97......8
50 .1.......491....5....2...3....8....9....8...1...7..4.6..2.1.58.2.3......9...76...
51 2.7.....869...5........74..7...41.2.....5..1.8..........2...83..19.......6.37...4
53 ......4.....4....5.31........9..82..12......92..59....6....19.....8.37..5.7....6.
59 8...4..5....751..3...9...........4....15..2...2.1.6....9..8.3.7..3.2..8.....9..1.
63 53..8.9......9....4.7.3.1.....6..4.2.5..48.172.1....8.......5........74.98.......
72 1..8...65......4317.36..8...4......8....2.....9...7.....635...2.......4.8395...7.
92 .7.8.463.....9..7..61.2.......9.8....4..85...8..4.6..7......4.3.....2.....2.....6
93 9..3..8.4.....2.9..6.4...1....28..6.82....1..64.5......1.92...3....1..4.1...5....

[Hajime]

rated 5.4

Probably hidden quad. But not necessarily needed.
I look for ALL naked/hidden pairs/triplets/quads before moving on.

[Pat]

Code: Select all


 3 . . | . . . | . . 2
 . 4 . | . 8 . | . 3 .
 6 . 2 | . . . | 4 . 5
-------+-------+------
 . . . | 7 . 4 | . . .
 . 2 . | . . . | . 7 .
 . . . | 5 . 3 | . . .
-------+-------+------
 2 . 8 | . . . | 9 . 6
 . 7 . | . 1 . | . 2 .
 5 . . | . . . | . . 7




you'd rate this "5.4" ???

(an un-needed quad)