The New Sudoku Players' Forum

by **claudiarabia** » Mon Jun 11, 2007 3:51 pm

re'born"][quote="claudiarabia"][quote="re'born"][quote="JPF wrote:
Code: Select all
1 . . | . . . | . . 2 . 3 . | 2 . 4 | . 5 . . . . | . . . | 6 . . -------+-------+------- . . 6 | . . . | 1 . . . . . | 7 . 3 | . . . . . 8 | . . . | 9 . . -------+-------+------- . . 1 | . . . | . . . . 7 . | 5 . 2 | . 3 . 8 . . | . . . | . . 9 ER=7.6

Code: Select all
*--------------------------------------------------------------------------------------* | 1 45689 4579 | 3689 356789 56789 | 3478 4789 2 | | 679 3 79* | 2 16789 4 | 78* 5 178 | | 24579 24589 24579 | 1389 135789 15789 | 6 14789 13478 | |----------------------------+----------------------------+----------------------------| | 234579 2459 6 | 489 24589 589 | 1 2478 34578 | | 2459 12459 2459 | 7 1245689 3 | 2458 2468 4568 | | 23457 1245 8 | 146 12456 156 | 9 2467 34567 | |----------------------------+----------------------------+----------------------------| | 234569 24569 1 | 34689 346789 6789 | 24578 24678 45678 | | 469 7 49* | 5 14689 2 | 48* 3 1468 | | 8 2456 2345 | 1346 13467 167 | 2457 12467 9 | *--------------------------------------------------------------------------------------*

...and the only 4 bivalued cells form a bidirectional y-cycle. It seems that SE finds this y-cycle, but what drives up the ER is that SE doesn't use the empty rectangle that leads (after an xy-wing) to a BUG+1. Instead, it uses "forcing chains" and "Nishio forcing chains".

Indeed, the Sudoku-Explainers oversees this kind of turbot fish. I found this puzzle, where the Explainer is taking resort to Nishio-Forcing-Chains while missing the Empty Rectangle too.

Code: Select all: +------------------+---------------+------------------+ | 56 56 8 | 39 2 349 | 7 349 1 | | 12 3 4 | 6 7 19 | 5 8 29 | | 9 12 7 | 8 5 134 | 26 346 2346 | +------------------+---------------+------------------+ | 148 178 *369 | 2 *369 5 | 69 14 47 | | 3456 569 2 | 7 1 369 | 8 3456 346 | | 1356 17 3569 | 4 369 8 | 269 1356 2367 | +------------------+---------------+------------------+ | 28 28 369 | 39 4 369 | 1 7 5 | | 356 569 *3569 | 1 -369 7 | 4 2 8 | | 7 4 1 | 5 8 2 | 3 69 69 | +------------------+---------------+------------------+

http://forum.enjoysudoku.com/viewtopic.php?t=3251&postdays=0&postorder=asc&start=0

So I will be alert if I will find an Empty rectangle, wenn the Explainer offers me nishios.

Claudia

by **JPF** » Wed Jun 20, 2007 9:16 pm

Puzzles for (almost) everybody

With Mauricio's pattern, here are a list of puzzles with an Explainer rating between 1.5 and 8.9

Mauricio's pattern:

Code: Select all: x . . | . . . | . . x . x . | x . x | . x . . . . | . . . | x . . -------+-------+------- . . x | . . . | x . . . . . | x . x | . . . . . x | . . . | x . . -------+-------+------- . . x | . . . | . . . . x . | x . x | . x . x . . | . . . | . . x

Code: Select all: ER # Puzzle 8.9 # 100000002030405010000000600006000700000302000005000400007000000080901030500000008 8.4 # 100000002030405060000000700007000600000803000005000900009000000010602030500000001 8.3 # 100000002030405010000000600006000700000803000004000500007000000010904030800000006 8.2 # 100000002030104050000000600007000800000608000002000500004000000010506030200000007 7.9 # 100000002030405010000000600006000700000308000004000500007000000080902030500000008 7.8 # 100000002030405060000000700007000200000803000009000100005000000080602030700000009 7.7 # 100000002030405060000000500007000200000803000006000100004000000080906030200000006 7.6 # 100000002030401050000000600002000700000305000008000300009000000040906030200000008 7.5 # 100000002030405010000000600007000800000603000005000200009000000050702040800000003 7.4 # 100000002030204050000000100001000600000503000007000800006000000020709030500000004 7.3 # 100000002030405060000000700002000600000308000005000900007000000040601030200000004 7.2 # 100000002030405060000000700007000200000307000006000800008000000040201030900000004 7.1 # 100000002030401050000000600002000500000307000008000100006000000040509030200000008 7.0 # 100000002030405060000000700005000600000803000007000900009000000080602040500000003 6.9 # 100000002030405060000000700002000800000309000007000600005000000090806030200000004 6.8 # 100000002030405060000000700007000500000601000002000800009000000050806030700000004 6.7 # 100000002030405010000000600006000700000703000008000200007000000020901030600000005 6.6 # 100000002030104050000000600001000700000703000006000500008000000070502040900000003 6.5 # 100000002030104050000000600007000800000603000002000500006000000010508030200000007 5.6 # 100000002030405060000000700005000600000308000007000200002000000040601030800000004 4.7 # 100000002030104050000000400006000700000308000002000500001000000080509030200000008 4.6 # 100000002030405060000000500007000100000106000002000800006000000050804030200000007 4.5 # 100000002030405060000000700002000500000803000009000600004000000080607050200000009 4.4 # 100000002030405060000000700002000800000304000007000100005000000060108040700000006 4.2 # 100000002030405060000000700007000100000803000008000400001000000060902030700000006 3.8 # 100000002030104050000000600006000700000308000002000800009000000040809030500000006 3.6 # 100000002030405010000000600007000500000308000006000200009000000040801030600000007 3.4 # 100000002030405060000000400001000700000306000002000800009000000050804030200000007 3.2 # 100000002030405060000000700005000200000703000008000100001000000070608040600000003 3.0 # 100000002030405060000000700002000800000309000007000500008000000040508030900000007 2.8 # 100000002030104050000000600007000500000803000006000900009000000040208030600000004 2.6 # 100000002030405060000000700007000800000602000005000900008000000020901030700000004 2.5 # 100000002030405060000000700007000800000309000002000100001000000050902030600000004 2.3 # 100000002030405010000000600006000700000304000008000900007000000040109030200000006 2.0 # 100000002030405060000000700007000200000301000008000100009000000050902030700000005 1.7 # 100000002030401050000000400002000600000607000008000500006000000070506010200000008 1.5 # 100000002030405060000000700007000500000801000002000600009000000050906040700000003

some interesting puzzles, according to Sudoku Explainer :

Code: Select all: 7.2 # 100000002030405010000000600006000700000308000001000900009000000040107030200000004 7.1 # 100000002030405010000000500002000600000307000008000400006000000090104030800000006 4.6 # 100000002030405060000000700007000200000306000008000400002000000090801030600000009 6.6 # 100000002030104050000000600007000200000305000006000800008000000040709030600000001 4.7 # 100000002030104050000000400006000700000308000002000500001000000080509030200000008

JPF

by **JPF** » Wed Jun 27, 2007 2:51 pm

Here's the new challenge :

Code: Select all: 1 . . | . . . | . . 2 . . . | 3 . 4 | . . . . . 3 | . . . | 5 . . -------+-------+------- . 5 . | . 2 . | . 6 . . . . | 6 . 1 | . . . . 7 . | . 8 . | . 3 . -------+-------+------- . . 6 | . . . | 2 . . . . . | 4 . 2 | . . . 8 . . | . . . | . . 1 ER=1.5

20 clues, minimal, singles (13 steps)

New rules :
In addition to the rules given above :

a proposed puzzle must be minimal
a proposed puzzle cannot have a ER higher than ER0 + 1.5 , ER0 beeing the previous posted ER.
nobody can post more than 5 puzzles within one week.
posts with several puzzles are allowed, provided that the above rules are satisfied.

Good luck !
[edited]

JPF

by **Mauricio** » Wed Jun 27, 2007 5:50 pm

JPF wrote:a proposed puzzle cannot have a ER higher than ER0 + 0.5 , ER0 beeing the previous posted ER.

Sudokus within that rule might be very hard to find. I rarely see sudokus with SE rating between 4.8 and 5.5. ER0+1.0 may be a better idea.

Code: Select all: 1 . . . . . . . 2 . . . 1 . 3 . . . . . 4 . . . 5 . . . 6 . . 1 . . 5 . . . . 4 . 6 . . . . 7 . . 5 . . 8 . . . 1 . . . 4 . . . . . 3 . 7 . . . 9 . . . . . . . 6 ER 2.0

by **JPF** » Wed Jun 27, 2007 7:58 pm

Mauricio wrote:Sudokus within that rule might be very hard to find. I rarely see sudokus with SE rating between 4.8 and 5.5. ER0+1.0 may be a better idea.

You are right, Mauricio.
It was not my intention.
[edited]
Let's take ER-ER0 <= 1.5

Code: Select all: 1 . . | . . . | . . 2 . . . | 3 . 4 | . . . . . 2 | . . . | 5 . . -------+-------+------- . 3 . | . 5 . | . 6 . . . . | 1 . 7 | . . . . 6 . | . 8 . | . 4 . -------+-------+------- . . 3 | . . . | 2 . . . . . | 6 . 8 | . . . 5 . . | . . . | . . 1 ER=2.6

JPF

by **Mauricio** » Wed Jun 27, 2007 9:27 pm

JPF wrote:Let's take ER-ER0 >= 1.5

I suppose you wanted to say ER-ER0 <= 1.5

Code: Select all: 1 . . . . . . . 2 . . . 1 . 3 . . . . . 4 . . . 5 . . . 6 . . 2 . . 1 . . . . 4 . 7 . . . . 8 . . 5 . . 7 . . . 2 . . . 4 . . . . . 3 . 8 . . . 7 . . . . . . . 5 ER 3.0

by **m_b_metcalf** » Thu Jun 28, 2007 8:41 am

JPF wrote:Here's the new challenge :

Gentlemen,
Much as I'd like to try my luck again, I'm out of the running until the end of August (but with the new rules and the smaller increment, maybe I'll still be able to participate, as the rate of progress will inevitably be smaller than before).

Regards,

Mike Metcalf
(now in Geneva)

by **JPF** » Thu Jun 28, 2007 11:06 am

Mauricio wrote:I suppose you wanted to say ER-ER0 <= 1.5

yes, of course, thanks.

m_b_metcalf (now in Geneva) wrote:Gentlemen,
Much as I'd like to try my luck again, I'm out of the running until the end of August (but with the new rules and the smaller increment, maybe I'll still be able to participate, as the rate of progress will inevitably be smaller than before).

Hm, I'm not sure

In any case, have a lot of fun in Europe, Mike.

My new proposal :

Code: Select all: 1 . . | . . . | . . 2 . . . | 3 . 4 | . . . . . 5 | . . . | 6 . . -------+-------+------- . 3 . | . 1 . | . 7 . . . . | 6 . 5 | . . . . 7 . | . 2 . | . 4 . -------+-------+------- . . 8 | . . . | 4 . . . . . | 7 . 9 | . . . 6 . . | . . . | . . 1 ER=3.2

Here are some missing rating values so far :

Code: Select all: +-----------+ |1..|...|..2| |...|3.4|...| |..2|...|5..| |---+---+---| |.4.|.3.|.6.| |...|1.7|...| |.6.|.5.|.3.| |---+---+---| |..7|...|2..| |...|6.8|...| |5..|...|..1| +-----------+ ER=1.5 ; 23 steps

ER=1.5 has been already proposed, but the number of steps here is interesting

Code: Select all: +-----------+ |1..|...|..2| |...|3.4|...| |..5|...|6..| |---+---+---| |.7.|.4.|.3.| |...|1.6|...| |.6.|.5.|.7.| |---+---+---| |..4|...|5..| |...|8.2|...| |8..|...|..1| +-----------+ ER=1.7

Code: Select all: +-----------+ |1..|...|..2| |...|3.4|...| |..5|...|6..| |---+---+---| |.3.|.7.|.5.| |...|2.6|...| |.5.|.8.|.9.| |---+---+---| |..2|...|8..| |...|7.9|...| |6..|...|..7| +-----------+ ER=2.3

Code: Select all: +-----------+ |1..|...|..2| |...|3.4|...| |..5|...|6..| |---+---+---| |.3.|.2.|.7.| |...|6.3|...| |.7.|.5.|.4.| |---+---+---| |..6|...|4..| |...|7.8|...| |2..|...|..5| +-----------+ ER=2.5

Code: Select all: +-----------+ |1..|...|..2| |...|3.4|...| |..5|...|1..| |---+---+---| |.3.|.2.|.6.| |...|7.5|...| |.6.|.8.|.4.| |---+---+---| |..7|...|5..| |...|6.8|...| |2..|...|..1| +-----------+ ER=2.8

JPF

by **JPF** » Fri Jun 29, 2007 10:33 pm

Ok, proposal of the day :

Code: Select all: 1 . . | . . . | . . 2 . . . | 3 . 4 | . . . . . 5 | . . . | 6 . . -------+-------+------- . 4 . | . 6 . | . 7 . . . . | 1 . 5 | . . . . 7 . | . 8 . | . 6 . -------+-------+------- . . 2 | . . . | 5 . . . . . | 8 . 7 | . . . 4 . . | . . . | . . 1 ER=3.4

JPF

by **JPF** » Tue Jul 03, 2007 3:07 pm

slowly but surely...

Code: Select all: 1 . . | . . . | . . 2 . . . | 3 . 4 | . . . . . 5 | . . . | 6 . . -------+-------+------- . 7 . | . 5 . | . 3 . . . . | 8 . 2 | . . . . 4 . | . 1 . | . 8 . -------+-------+------- . . 3 | . . . | 5 . . . . . | 7 . 9 | . . . 8 . . | . . . | . . 1 ER=3.6

JPF

by ab » Tue Jul 03, 2007 5:38 pm

here's a 4.4:

Code: Select all: 9 . . | . . . | . . 3 . . . | 8 . 4 | . . . . . 7 | . . . | 9 . . ------+-------+------ . 6 . | . 5 . | . 8 . . . . | 3 . 7 | . . . . 8 . | . 2 . | . 4 . ------+-------+------ . . 9 | . . . | 7 . . . . . | 2 . 6 | . . . 3 . . | . . . | . . 5

by ab » Tue Jul 03, 2007 5:45 pm

and a 4.5:

Code: Select all: 4 . . | . . . | . . 1 . . . | 8 . 9 | . . . . . 1 | . . . | 2 . . ------+-------+------ . 3 . | . 7 . | . 9 . . . . | 5 . 1 | . . . . 9 . | . 2 . | . 4 . ------+-------+------ . . 5 | . . . | 3 . . . . . | 4 . 3 | . . . 8 . . | . . . | . . 2

by **m_b_metcalf** » Wed Jul 04, 2007 9:25 am

JPF wrote:In any case, have a lot of fun in Europe, Mike.

Ah, ha! It is going slowly enough for me perhaps to be able to join in later.

Regards,

Mike Metcalf
(from a wet and cold Rougemont (Doubs))

by **JPF** » Wed Jul 04, 2007 8:14 pm

here's the next step :

Code: Select all: 1 . . | . . . | . . 2 . . . | 3 . 4 | . . . . . 5 | . . . | 1 . . -------+-------+------- . 6 . | . 2 . | . 7 . . . . | 8 . 1 | . . . . 7 . | . 5 . | . 3 . -------+-------+------- . . 2 | . . . | 5 . . . . . | 7 . 6 | . . . 8 . . | . . . | . . 6 ER=4.6

for the record :

Code: Select all: +-----------+ |1..|...|..2| |...|3.4|...| |..4|...|5..| |---+---+---| |.5.|.6.|.7.| |...|8.2|...| |.3.|.1.|.4.| |---+---+---| |..8|...|6..| |...|7.3|...| |2..|...|..8| +-----------+ ER=4.2

JPF

by **Mauricio** » Fri Jul 06, 2007 3:27 pm

Let chains begin.

Code: Select all: 1 . .|. . .|. . 2 . . .|3 . 4|. . . . . 2|. . .|5 . . -----+-----+----- . 3 .|. 1 .|. 6 . . . .|2 . 7|. . . . 8 .|. 5 .|. 4 . -----+-----+----- . . 5|. . .|1 . . . . .|9 . 3|. . . 4 . .|. . .|. . 7 ER 5.6

The New Sudoku Players' Forum

Patterns Game 1.0

empty rectangle