7-men Syzygy attempt

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Vinvin
Posts: 5228
Joined: Thu Mar 09, 2006 9:40 am
Full name: Vincent Lejeune

Re: 7-men Syzygy attempt

Post by Vinvin »

syzygy wrote:I am wondering about this:
ftp://112.73.74.24/pub/syzygy/7men_testing/KRRPPPvK.txt

Longest win for white: 13 ply; 8/8/1P6/RP6/RP6/8/2k5/K7 b - -
[D]8/8/1P6/RP6/RP6/8/2k5/K7 b - -

Why can white not respond to any move by black with b7?
I don't understand very well your question but I ran the position with SF-MF for the 6 legal moves for black :

Code: Select all

Stockfish_180407_matefinder:
...
 30/9	00:00	 1 280k	18 033k	+M4	1. ... Kd1 2.Ra2 Ke1 3.Rg2 Kd1 4.Raa2 Ke1 5.Rg1+
 30/9	00:00	 1 280k	18 033k	+M4	1. ... Kc1 2.Ra2 Kd1 3.Rf2 Ke1 4.Raa2 Kd1 5.Rf1+
 30/9	00:00	 1 280k	18 033k	+M4	1. ... Kd2 2.Ra3 Kc2 3.Rg3 Kd2 4.Ra2+ Kc1 5.Rg1+
 30/13	00:00	 1 280k	18 033k	+M6	1. ... Kb3 2.b7 Kc4 3.b8Q Kd5 4.b6+ Ke6 5.Re5+ Kf7 6.Ra7+ Kg6 7.Qd6+
 30/13	00:00	 1 280k	18 033k	+M6	1. ... Kc3 2.b7 Kd4 3.b6 Ke3 4.Ra3+ Kf2 5.Rb3 Kg1 6.Ra2 Kf1 7.Rb1+
 30/13	00:00	 1 280k	18 033k	+M6	1. ... Kd3 2.b7 Ke4 3.b8Q Kf5 4.b6+ Ke6 5.Re5+ Kf7 6.Ra7+ Kg6 7.Qd6+
Vinvin
Posts: 5228
Joined: Thu Mar 09, 2006 9:40 am
Full name: Vincent Lejeune

Re: 7-men Syzygy attempt

Post by Vinvin »

syzygy wrote:For comparison, in KRRPPvK max DTZ is 6 ply:
[D]KRR5/PP6/8/8/8/8/8/k7 b
which makes sense.
Here, maximum is mate in 5, so 10 plies :

Code: Select all

Stockfish_180407_matefinder:
...
 105/9	00:00	 1 163k	4 525k	+M4	1. ... Kb1 2.Rc6 Ka2 3.Rbc8 Kb2 4.b8Q+ Ka2 5.Ra6+
 105/11	00:00	 1 163k	4 525k	+M5	1. ... Ka2 2.Rc6 Kb3 3.Rbc8 Kb4 4.b8Q+ Ka5 5.Rc1 Ka4 6.Ra1+
 105/11	00:00	 1 163k	4 525k	+M5	1. ... Kb2 2.Rc6 Ka3 3.Rbc8 Kb4 4.b8Q+ Ka5 5.Rc1 Ka4 6.Ra1+
koedem
Posts: 105
Joined: Fri Mar 18, 2016 10:45 pm

Re: 7-men Syzygy attempt

Post by koedem »

Vinvin wrote:
syzygy wrote:I am wondering about this:
ftp://112.73.74.24/pub/syzygy/7men_testing/KRRPPPvK.txt

Longest win for white: 13 ply; 8/8/1P6/RP6/RP6/8/2k5/K7 b - -
[D]8/8/1P6/RP6/RP6/8/2k5/K7 b - -

Why can white not respond to any move by black with b7?
I don't understand very well your question but I ran the position with SF-MF for the 6 legal moves for black :

Code: Select all

Stockfish_180407_matefinder:
...
 30/9	00:00	 1 280k	18 033k	+M4	1. ... Kd1 2.Ra2 Ke1 3.Rg2 Kd1 4.Raa2 Ke1 5.Rg1+
 30/9	00:00	 1 280k	18 033k	+M4	1. ... Kc1 2.Ra2 Kd1 3.Rf2 Ke1 4.Raa2 Kd1 5.Rf1+
 30/9	00:00	 1 280k	18 033k	+M4	1. ... Kd2 2.Ra3 Kc2 3.Rg3 Kd2 4.Ra2+ Kc1 5.Rg1+
 30/13	00:00	 1 280k	18 033k	+M6	1. ... Kb3 2.b7 Kc4 3.b8Q Kd5 4.b6+ Ke6 5.Re5+ Kf7 6.Ra7+ Kg6 7.Qd6+
 30/13	00:00	 1 280k	18 033k	+M6	1. ... Kc3 2.b7 Kd4 3.b6 Ke3 4.Ra3+ Kf2 5.Rb3 Kg1 6.Ra2 Kf1 7.Rb1+
 30/13	00:00	 1 280k	18 033k	+M6	1. ... Kd3 2.b7 Ke4 3.b8Q Kf5 4.b6+ Ke6 5.Re5+ Kf7 6.Ra7+ Kg6 7.Qd6+
The question was why the position is not DTZ 1 since b7 is a zeroing move. (but the Syzygy table claims the fastest available winning zeroing move is in 13 plies.
But it seems Ronald found the problem (an overflow it seems; not that I actually understand what the code is doing :D)
noobpwnftw
Posts: 560
Joined: Sun Nov 08, 2015 11:10 pm

Re: 7-men Syzygy attempt

Post by noobpwnftw »

Regeneration has started for those with pawns using updated generator.
Better to discover problems now than later, when those files are regenerated, rsync can compare and update file time on FTP if something has changed, including the stats file.
syzygy
Posts: 5557
Joined: Tue Feb 28, 2012 11:56 pm

Re: 7-men Syzygy attempt

Post by syzygy »

koedem wrote:The question was why the position is not DTZ 1 since b7 is a zeroing move. (but the Syzygy table claims the fastest available winning zeroing move is in 13 plies.
But it seems Ronald found the problem (an overflow it seems; not that I actually understand what the code is doing :D)
Basically the generator was seeing the second pawn in the wrong position some of the time (on b2 instead of b7, for example).
koedem
Posts: 105
Joined: Fri Mar 18, 2016 10:45 pm

Re: 7-men Syzygy attempt

Post by koedem »

On an unrelated note, I was checking some other TB position and stumbled upon this position https://syzygy-tables.info/?fen=6Q1/5NR ... _b_-_-_0_1
Why does the DTZ value of the position vs the one of the top move, down the top line look so weird? Am I missing something?
syzygy
Posts: 5557
Joined: Tue Feb 28, 2012 11:56 pm

Re: 7-men Syzygy attempt

Post by syzygy »

koedem wrote:On an unrelated note, I was checking some other TB position and stumbled upon this position https://syzygy-tables.info/?fen=6Q1/5NR ... _b_-_-_0_1
Why does the DTZ value of the position vs the one of the top move, down the top line look so weird? Am I missing something?
The value I see is 2, which is off by one. That is normal. The DTZ value is stored in moves unless having it in plies is critical for the 50-move rule. Converting it to plies cannot be done fully accurately.
syzygy
Posts: 5557
Joined: Tue Feb 28, 2012 11:56 pm

Re: 7-men Syzygy attempt

Post by syzygy »

Just in case Bojun is reading this and not the github thread, unfortunately the "fixed" generator was still not completely fixed.

For example, the win in 17 ply reported for KQBBPPvK is wrong:
ftp://112.73.74.24/pub/syzygy/7men_testing/KQBBPPvK.txt

I found another problem (very similar to the first one) and I hope it is fixed now. Again, only TB files with two or more pawns should be affected (including PvP if any such files have been generated).
noobpwnftw
Posts: 560
Joined: Sun Nov 08, 2015 11:10 pm

Re: 7-men Syzygy attempt

Post by noobpwnftw »

Affected files has been moved into folder 7men_bad_backup2, regeneration has started with new generator build.
koedem
Posts: 105
Joined: Fri Mar 18, 2016 10:45 pm

Re: 7-men Syzygy attempt

Post by koedem »

syzygy wrote:
koedem wrote:On an unrelated note, I was checking some other TB position and stumbled upon this position https://syzygy-tables.info/?fen=6Q1/5NR ... _b_-_-_0_1
Why does the DTZ value of the position vs the one of the top move, down the top line look so weird? Am I missing something?
The value I see is 2, which is off by one. That is normal. The DTZ value is stored in moves unless having it in plies is critical for the 50-move rule. Converting it to plies cannot be done fully accurately.
I mean, Qb2+ is DTZ1 but when making it Whites Kd1 is DTZ2. I would think DTZ shouldn't go up when you aren't zeroing.