Scratch Chess Engine - Game of Kings

waabooboo

ArnoHu wrote:
waabooboo wrote:
Wolverine changes merged to the main project: improved transposition table, and internal iterative deepening. Search depth is higher now, especially in endgame.

Congrats to this 95% vs. 95% draw against GoK Classic:
https://lichess.org/study/nHWsefvf/hAEJOVje

Classic had one possibility during endgame, but that line it would not discover as long as LMR was on, and without LMR it would have taken 22sec on depth 13. No chance in a 5-sec game.

Thanks! Some strong play from Wolverine.

Just out of curiousity, the two previous games where Wolverine played Rf8 instead of castling, was that the current Wolverine or the previous one? I could not reproduce that move for either version – and it's a really stupid move too.

I had an extra eval bonus for actually castling, but I got rid of it because it destabilized things – the evals would jump when Wolverine calculated to a position where it had castled. But I haven't seen Wolverine play like that recently…

waabooboo

ArnoHu wrote:
ArnoHu wrote:
waabooboo wrote:
Wolverine changes merged to the main project: improved transposition table, and internal iterative deepening. Search depth is higher now, especially in endgame.

Congrats to this 95% vs. 95% draw against GoK Classic:
https://lichess.org/study/nHWsefvf/hAEJOVje

Classic had one possibility during endgame, but that line it would not discover as long as LMR was on, and without LMR it would have taken 22sec on depth 13. No chance in a 5-sec game.

GoK Classic with a perfect game against Wolverine 2, 99% vs. 92%:
https://lichess.org/study/nHWsefvf/eUkYXI12

That one's hard to beat. 7. Nh4 is stupid, but Wolverine's position is already really bad. Opening book would help I guess, but Wolverine should be able to play well without one.

ArnoHu

GoK NNUE vs. Black Crow, 98% vs. 93%:
https://lichess.org/study/nHWsefvf/6l8PIRIv

ArnoHu

New GoK Classic with improved pawn positional evaluation:

GoK Classic vs. Shallow Blue 3 Dev, 92% vs. 87%:
https://lichess.org/study/nHWsefvf/HpSVq06C

GoK Classic vs. Delta, 97% vs. 97%:
https://lichess.org/study/nHWsefvf/FfEGCaEb

GoK Classic vs. White Dove, 87% vs. 87%:
https://lichess.org/study/nHWsefvf/3O5bNGdi

GoK Classic vs. Wolverine 2, 97% vs. 91%:
https://lichess.org/study/nHWsefvf/vHc0zVZC

With an other minor update, those are the results:

GoK Classic vs. Shallow Blue 3 Dev, 93% vs. 90%:
https://lichess.org/study/nHWsefvf/qe3yMidA

GoK Classic vs. Delta, 94% vs. 90%:
https://lichess.org/study/nHWsefvf/qFoOsWGG

GoK Classic vs. White Dove, 96% vs. 92%:
https://lichess.org/study/nHWsefvf/10hI9fal

GoK Classic vs. Wolverine 2, 87% vs. 83%:
https://lichess.org/study/nHWsefvf/f5UCnF6y

Last edited by ArnoHu (Oct. 11, 2025 12:52:56)

ArnoHu

GoK Classic vs. White Dove, 86% vs. 83%:
https://lichess.org/study/nHWsefvf/yyOQiwMD

GoK Classic vs. Wolverine 2, 87% vs. 78%:
https://lichess.org/study/nHWsefvf/js4wVmzb

waabooboo

ArnoHu wrote:
GoK Classic vs. White Dove, 86% vs. 83%:
https://lichess.org/study/nHWsefvf/yyOQiwMD

GoK Classic vs. Wolverine 2, 87% vs. 78%:
https://lichess.org/study/nHWsefvf/js4wVmzb

Looks like futility pruning cost Wolverine this game… I currently allow it up to 4 plies from the horizon, so there's a bunch of lines where Wolverine prunes forward after rook takes queen, overlooking Rg8# on the next turn.

With futility pruning disabled, Wolverine senses the danger within the 5 second time limit and avoids the mate. But I think disabling this harms his overall quality of play. I'm curious how GoK handles futility pruning, if there's a better way to do it.

Edit: I guess what I have implemented is reverse futility pruning, not standard futility pruning. I check if static eval > beta + margin before looping through the moves, and if the condition is true then I fail high immediately.

Last edited by waabooboo (Oct. 13, 2025 11:47:36)

ArnoHu

waabooboo wrote:
ArnoHu wrote:
GoK Classic vs. White Dove, 86% vs. 83%:
https://lichess.org/study/nHWsefvf/yyOQiwMD

GoK Classic vs. Wolverine 2, 87% vs. 78%:
https://lichess.org/study/nHWsefvf/js4wVmzb

Looks like futility pruning cost Wolverine this game… I currently allow it up to 4 plies from the horizon, so there's a bunch of lines where Wolverine prunes forward after rook takes queen, overlooking Rg8# on the next turn.

With futility pruning disabled, Wolverine senses the danger within the 5 second time limit and avoids the mate. But I think disabling this harms his overall quality of play. I'm curious how GoK handles futility pruning, if there's a better way to do it.

Edit: I guess what I have implemented is reverse futility pruning, not standard futility pruning. I check if static eval > beta + margin before looping through the moves, and if the condition is true then I fail high immediately.

GoK Classic vs. Wolverine 2, 91% vs. 86%:
https://lichess.org/study/nHWsefvf/bbFXfCxI

GoK's game was better than it looks like, blunder 1 prevented in 9.8sec, blunders 2+3 were m7's it didnt see

Last edited by ArnoHu (Oct. 14, 2025 06:13:38)

ArnoHu

GoK Classic vs. White Dove, 97% vs. 92%:
https://lichess.org/study/nHWsefvf/yJZVK22z

GoK Classic vs. Delta, 89% vs. 89%:
https://lichess.org/study/nHWsefvf/yCpon3ai

GoK Classic vs. Shallow Blue 3 Dev, 92% vs. 85%:
https://lichess.org/study/nHWsefvf/37nDopPX

GoK Classic vs. Wolverine 2, 97% vs. 92%:
https://lichess.org/study/nHWsefvf/S58aEapL

Last edited by ArnoHu (Oct. 14, 2025 17:15:48)

ArnoHu

ArnoHu wrote:
GoK Classic vs. White Dove, 97% vs. 92%:
https://lichess.org/study/nHWsefvf/yJZVK22z

GoK Classic vs. Delta, 89% vs. 89%:
https://lichess.org/study/nHWsefvf/yCpon3ai

GoK Classic vs. Shallow Blue 3 Dev, 92% vs. 85%:
https://lichess.org/study/nHWsefvf/37nDopPX

GoK Classic vs. Wolverine 2, 97% vs. 92%:
https://lichess.org/study/nHWsefvf/S58aEapL

Just one more improvement on king ring attacker weights, and GoK Classic plays a perfect game against White Dove, 98% vs. 91%:
https://lichess.org/study/nHWsefvf/ZoDcrGj3

GoK Classic vs. Wolverine 2, 94% vs. 92%:
https://lichess.org/study/nHWsefvf/vgPLbV65

GoK Classic vs. Delta, 95% vs. 90%:
https://lichess.org/study/nHWsefvf/h39llBU8

Last edited by ArnoHu (Oct. 15, 2025 02:01:23)

ArnoHu

ArnoHu wrote:
ArnoHu wrote:
GoK Classic vs. White Dove, 97% vs. 92%:
https://lichess.org/study/nHWsefvf/yJZVK22z

GoK Classic vs. Delta, 89% vs. 89%:
https://lichess.org/study/nHWsefvf/yCpon3ai

GoK Classic vs. Shallow Blue 3 Dev, 92% vs. 85%:
https://lichess.org/study/nHWsefvf/37nDopPX

GoK Classic vs. Wolverine 2, 97% vs. 92%:
https://lichess.org/study/nHWsefvf/S58aEapL

Just one more improvement on king ring attacker weights, and GoK Classic plays a perfect game against White Dove, 98% vs. 91%:
https://lichess.org/study/nHWsefvf/ZoDcrGj3

GoK Classic vs. Wolverine 2, 94% vs. 92%:
https://lichess.org/study/nHWsefvf/vgPLbV65

GoK Classic vs. Delta, 95% vs. 90%:
https://lichess.org/study/nHWsefvf/h39llBU8

GoK Classic vs. Shallow Blue 3 Dev, 92% vs. 86%:
https://lichess.org/study/nHWsefvf/8iaXTSk6

GoK Classic vs. White Dove, 92% vs. 87%:
https://lichess.org/study/nHWsefvf/cJjjLc5d

GoK Classic vs. White Dove, 94% vs. 85%:
https://lichess.org/study/nHWsefvf/IpIRYoWO

GoK Classic vs. Delta, 93% vs. 88%:
https://lichess.org/study/nHWsefvf/3L33Lee0

coooolboy55

What activations do you use for your NNUEs?

Destructor_chess

coooolboy55 wrote:
What activations do you use for your NNUEs?

reLu I think

ArnoHu

Destructor_chess wrote:
coooolboy55 wrote:
What activations do you use for your NNUEs?
reLu I think

Correct!

ArnoHu

GoK Classic vs. White Dove, 96% vs. 90%:
https://lichess.org/study/7cqWfi6q/rhnmquUT

GoK Classic vs. Delta, 85% vs. 80%:
https://lichess.org/study/7cqWfi6q/Tf1LHjLF

GoK Classic vs. Shallow Blue 3 Dev, 94% vs. 93%:
https://lichess.org/study/7cqWfi6q/7rLDSYiv

GoK Classic vs. Wolverine 2, 98% vs. 97%:
https://lichess.org/study/7cqWfi6q/WpKjyJ9D

GoK Classic vs. Wolverine 2, 87% vs. 83%:
https://lichess.org/study/7cqWfi6q/tb85ykvi

GoK Classic vs. Shallow Blue 3 Dev, 92% vs. 88%:
https://lichess.org/study/7cqWfi6q/vzySbbzJ

Last edited by ArnoHu (Oct. 16, 2025 10:01:58)

WhiteDoveOfficial

coooolboy55 wrote:
What activations do you use for your NNUEs?

BC uses ScReLU as generally speaking it gives slightly better results compared to standard ReLU.

Destructor_chess

WhiteDoveOfficial wrote:
coooolboy55 wrote:
What activations do you use for your NNUEs?

BC uses ScReLU as generally speaking it gives slightly better results compared to standard ReLU.

But the training is more noisy I think, and it takes more ressources.

waabooboo

New Wolverine version out, with some more improvements to the transposition table. This helps endgame search depth quite a bit.

https://imgur.com/a/fZhYKqb – I think Wolverine will not lose endgames like this any more

ArnoHu

waabooboo wrote:
New Wolverine version out, with some more improvements to the transposition table. This helps endgame search depth quite a bit.

https://imgur.com/a/fZhYKqb – I think Wolverine will not lose endgames like this any more

Plays pretty well, esp. midgame:
https://lichess.org/study/7cqWfi6q/NjTsbPil

Destructor_chess

Do you store checkmates in TT wabooboo?

Destructor_chess

Wich think time for this depth? 5 sec?

waabooboo wrote:
New Wolverine version out, with some more improvements to the transposition table. This helps endgame search depth quite a bit.

https://imgur.com/a/fZhYKqb – I think Wolverine will not lose endgames like this any more

10?

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