Moby Dam

[Krzysztof Grzelak]

Thank you for the new version of the program Harm.

[Birdy]

Hello all, just a heads-up that a new release of Moby Dam is available. (...)

Thank you so much for sharing Moby Dam's third version.

It's incredible to see that the "original" Dam has already 20 years (1999)!!

[Krzysztof Grzelak]

Request to Harm Jetten.

What to do to make the engine continue to play after exceeding the moves for the game and there is no message about the end of the game. For example, I set the program to 15 minutes for 75 moves and after 75 moves it doesn't play anymore.

[Harm Jetten]

Hi Krzysztof,

You can set the number of moves to 0 instead of 75; 0 means "unlimited" moves.
Of course Moby Dam will then play a bit faster so by move 75 it will have used maybe 12 or 13 minutes, to account for the possibility that the game will be much longer.

[Ed Gilbert]

I set the program to 15 minutes for 75 moves and after 75 moves it doesn't play anymore.

You told it that the game would end after 75 moves, so the program behavior after that is not defined by your match rules. The state of the program and how it thinks and moves at that point is left to the discretion of the program designer.

[ildjarn]

An idea to extend the move/time format would be to separate multiple formats with a ;, with a * as 'repeat last format ad infinitum'.

E.g. the old time format for games was '50 moves in 2 hours, and then all next 25 moves in 1 hour', which would lead to time format '50:120;25:60;*'.
Or '75 moves in 15 minutes, and then 5 minutes to finish the game': '75:15;0:5'.

[Krzysztof Grzelak]

An idea to extend the move/time format would be to separate multiple formats with a ;, with a * as 'repeat last format ad infinitum'.

E.g. the old time format for games was '50 moves in 2 hours, and then all next 25 moves in 1 hour', which would lead to time format '50:120;25:60;*'.
Or '75 moves in 15 minutes, and then 5 minutes to finish the game': '75:15;0:5'.

But yes you can like you are using Linux or Windows.

[Krzysztof Grzelak]

Hi Krzysztof,

You can set the number of moves to 0 instead of 75; 0 means "unlimited" moves.
Of course Moby Dam will then play a bit faster so by move 75 it will have used maybe 12 or 13 minutes, to account for the possibility that the game will be much longer.

Thank you for your answer Harm.

[Harm Jetten]

Hello everyone,

Good news! A new version of Moby Dam is out. There are two main changes: multi-threaded search, and pattern based evaluation. The playing strength has improved quite a bit, though not to the level of Scan and Kingsrow.

The program can be downloaded at https://hjetten.home.xs4all.nl/mobydam/mobydam.html (bottom of the page)

Enjoy!

[Krzysztof Grzelak]

Thank you Harm.

[BertTuyt]

Harm, what a really positive surprise !
Thanks for sharing.

You wrote that is does not match kingsrow/scan yet, what is the elo difference (guess you did some 158 games dxp matches?

And is there a specific reason you did not go for nnue (although patterns is still the better/faster option).

Bert

[Harm Jetten]

Hi Bert,

Here are some recent results of Moby Dam 2023 against Kingsrow and Scan.
All programs use 6-piece egdb, 512MB tt, 1 thread and no pondering.
DXP match settings 1 minute for 80 moves, on my i3 12100.

kr 1.63 vs moby
results for first engine: +144 -3 =1498 ?5 54.3%

sc 3.1 vs moby
results for first engine: +119 -4 =1520 ?7 53.5%

sc 2.0 vs moby
results for first engine: +73 -29 =1532 ?16 51.3%

I wanted to "catch up" with the stronger programs and was curious what would be the simplest configuration of patterns to get a decent result; Moby Dam uses 9 patterns of 4x4. I also tried 16 patterns recently, and strangely the results were slightly worse.

Maybe I needed more games to train with; right now it's approx. 310k games = 22M positions. These games are mostly Moby Dam against DragonDraughts, Kingsrow and Scan with DXP settings of 1 minute for 80 moves.

After first taking a break for now, I do want to try and implement NNUE in the next version.

[Sidiki]

Hi Harm,

Thanks very much for this update.
The August Tournament will be exciting.

Friendly, Sidiki.