Search found 1437 matches

by jp
Wed Jan 13, 2021 7:19 am
Forum: Computer Chess Club: General Topics
Topic: Interesting Puzzle for Engines
Replies: 10
Views: 741

Re: Interesting Puzzle for Engines

So is everything other than ...a4 a certain draw?
(I do now see Mike's output: 44 +0.29 439.2M 0:02.87 b5 ...)


What moves instead of 13. Kh3 (just before the position) give White a draw?
by jp
Tue Jan 12, 2021 6:54 am
Forum: Computer Chess Club: General Topics
Topic: Sting SF 25
Replies: 18
Views: 2723

Re: Sting SF 25

If the authors of GUIs will add such an obvious and simple possibility, each engine can use auto-play(ing) instantly. They are ready to do it now! But we can always play engine vs. engine games from the position, and it can be the same engine playing against itself. If you start the auto-play(ing),...
by jp
Tue Jan 12, 2021 6:48 am
Forum: Computer Chess Club: General Topics
Topic: Interesting Puzzle for Engines
Replies: 10
Views: 741

Re: Interesting Puzzle for Engines

In my Kings & Pawns tests, I found a interesting endgame problem which I believe lots of engines won't see quickly. (My computer needed lots of time to even realize this) For copying: 8/1p6/4k1pp/p1p1p3/4P3/1PP4K/P2P3P/8 b - - 0 13 As you see the below, both Eman and Ethereal didn't see a4! and a w...
by jp
Wed Dec 30, 2020 3:41 am
Forum: Computer Chess Club: General Topics
Topic: Draw by 3 fold repetition...
Replies: 33
Views: 1000

Re: Draw by 3 fold repetition...

The Play Magnus engine does appear not to know the 3-fold-repetition rule, allowing draws in totally winning positions. Glaurung (on which it was based) is open source. It might be interesting to look inside the code to see what's going on.
by jp
Fri Dec 25, 2020 9:41 am
Forum: Computer Chess Club: General Topics
Topic: what is the longest tablebase mate with special properties?
Replies: 16
Views: 1708

Re: what is the longest tablebase mate with special properties?

3k4/8/3K4/3R4/3p3r/6P1/8/8 w - - 0 1 Mate in 6, dual-free (with best play only), winner complexity = 2. 1. gxh4 Ke8 2. Ke6 Kf8 3. Kf6 Kg8 4. Rxd4 Any deviation so far by White (Black) allows slower (faster) mate. But now Black has a choice: a) 4. ... Kh7 5. Rd8 Kh6 6. Rh8# b) 4. ... Kh8 5. Kg6 Kg8 ...
by jp
Fri Dec 25, 2020 2:05 am
Forum: Computer Chess Club: General Topics
Topic: what is the longest tablebase mate with special properties?
Replies: 16
Views: 1708

Re: what is the longest tablebase mate with special properties?

It seems problemists call single-path problems "dual-free", so I'll switch to that terminology.

What I'd like to see is dual-free mates with high winner complexity (at least greater than 1, but greater than 2 would be better still).
by jp
Thu Dec 24, 2020 6:47 am
Forum: Computer Chess Club: General Topics
Topic: Sting SF 25
Replies: 18
Views: 2723

Re: Sting SF 25

For the above-mentioned "IQ" test I had selected positions containing possible problems for some "classic" alpha-beta ("ELO") engines, and next I grouped it by reasons. Sting is a try to solve the positions (problems). In my opinion an engine solving all (100/100) the positions (of course without t...
by jp
Wed Dec 23, 2020 2:43 am
Forum: Computer Chess Club: General Topics
Topic: Sting SF 25
Replies: 18
Views: 2723

Re: Sting SF 25

The main goal of my work is to prove that a chess (alpha-beta) engine is able, without some dirty tricks or external tools or selective code or artifical intelligence, to solve all positions from the above-mentioned "IQ" test. I believe that it is possible to do (implement) it without any ELO loss ...
by jp
Fri Dec 18, 2020 7:07 am
Forum: Computer Chess Club: General Topics
Topic: what is the longest tablebase mate with special properties?
Replies: 16
Views: 1708

Re: what is the longest tablebase mate with special properties?

Extra terminology: Let me distinguish different complexities. Loser complexity is the complexity of the loser's moves. Winner complexity is the complexity of the winner's moves. Then in Uri's composition k7/P3p3/1q2Pp2/K1p1pP2/1pPpPp2/1P1P1P2/B7/b7 w - - 2 1 (#11 with a single path for the winner) t...
by jp
Thu Dec 17, 2020 1:35 am
Forum: Computer Chess Club: General Topics
Topic: An idea for a different type of tournament
Replies: 59
Views: 13382

Re: An idea for a different type of tournament

If we give Black a- and h-pawns to make it harder for White to mate by promoting a pawn (as above, for 4k3/8/8/8/8/8/PPPPPPPP/RNB1KBNR w KQkq) ...



... then SF11 fails to announce mate at depth 30, PV=2.