World Draughts Forum

Robin, congrats on DarkHorse, it sounds like it is very strong, and I am looking forward to trying it. My computer has been tied up recently building more databases, but it will be finished soon and then I can start doing some of the other projects that I have been postponing.
Thanks for sharing ...

I have the Dragon 2 through 7 pieces db on Mega here: https://mega.nz/file/iAB2DCRK#Xk4G6XQRM ... 86zwghkofE

I documented the DXP additions for Fischer time control in a forum post 10 years ago. I will paste it below. Also, to enable its use in kingsrow, there needs to be a file named "kingsrow.ini" in the directory Documents\Ed Gilbert\Kingsrow International. An empty file will work.

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I added ...

Gijsbert, thank you for posting some of the details about how you interact with Codex. Very helpful.
I tried version 1.7 of the GUI and got tournaments running with mobydam. It turns out I had misunderstood your instructions for interfacing to mobydam and had not changed the setting of gui-send ...

Version 1.4 is published on github. You should be able to play a match between Kingsrow and Mobydam with this version.
I have downloaded GWGUI version 1.6 and started to play with it. I am trying to run a hub tournament between kingsrow and the latest version of moby dam, Moby Dam_May 15 2026. The ...

Good point, currently 'go ponder' behaves as 'go analyze'. Perhaps we can have a quick show of hands here: do all engines support 'go analyze', so when browsing a game the GUI continuously sends 'go analyze'? 'go ponder' should work as Harm/UCI mentions?

Kingsrow supports both go analyze and go ...

I have tested this version with the latest mobydam.exe, and mobydam requires 'hub' as the first argument to launch it in hub mode. 'We' have added that option to the engine-parameters dialog box, so before you open mobydam you first edit the engine-parameters and set 'launch-hub-argument' to 'hub ...

I found the root cause. My 'International Draughts GUI' was sending a 'K' after a promotion. GWD didn't care but Kingsrow does.

Ah good. I was almost finished typing a rather long response when I saw that you found the problem.

In general I think you should only send the most recent moves ...

In American 8x8 checkers, when they realized there were too many draws, they started using more difficult start positions. First they used 2-move openings, and then later changed to 3-move openings. For 10x10 draughts, a similar idea might be to use a set of difficult start positions to get more ...

BertTuyt wrote: Sun Sep 21, 2025 14:55 The perft result from Ed was (most likely) without bulk-counting, which should not be neglected.

I looked at some old commits in SVN. Bulk counting was added on July 17, 2008.

My newest PC is a laptop with an I7-12700H CPU. Base clock is 2.4 GHz, but it gets up to about 4.5 GHz with turbo boost.

perft(1) 9 nodes, 0.00 sec, 9 knodes/sec
perft(2) 81 nodes, 0.00 sec, 81 knodes/sec
perft(3) 658 nodes, 0.00 sec, 658 knodes/sec
perft(4) 4265 nodes, 0.00 sec, 4265 knodes/sec ...

If you only want to know if it is a definitive win for black, without determining the path to win, you can do a 100 ply minimal window search in move 12 for white. Depending on your score for definite win, one can use a window such as -1000 .. -999. If it fails low, you are sure that black wins ...

I let kingsrow play it out in autoplay at 2min/move, 16 search threads, and it ended in a black win. Of course that's not definitive. A better way to analyze it is using dropout expansion, to automatically explore all reasonable lines of play and build a db. It would probably take days or even weeks ...

At first glance I thought the black/white positions might be symmetrical mirrors, but they aren't quite, the man on 43 would have to be moved to 44.

Kingsrow thinks that white's first really weak move was 11. 39-33. The search score jumps from 12 to 56 almost instantly. 50-45 instead maintains a ...

Flits (white) played 38-33 and the game was concluded soon as a win for Kingsrow.
A better defense seems to be 40-35 (9-14) 32-28 (21-27) 37-32 (27-31 or 14-20) with a possible draw.
I'm not sure this sequence is right and that this ends in a draw, Ed might have the final verdict here.

Kingsrow ...