policy network

[BertTuyt]

With the policy network developed I asked Codex to optimize the LMR in relation to the policy output, in such a way that at least the number of nodes and/or time was reduced with 50%.

Codex did several experiments, the total time spent by Codex was around 1 hour.
I also asked Codex to write a report in the end.
All code changes were also implemented by the AI in an experimental version of the Damage engine (version 18.4).

I did not have time to study the extensive report in detail, see attached.

As a proof of the pudding a 158 games DXP match was played against KR, settings no book, 6p DB, 1 core, and 80 moves for 1 minute.
Match result 158 draws. See also attached file.

This result is not yet optimized, but as I believe we have reached a ceiling I don't expect there is much ELO to gain.

Bert

[Joost Buijs]

For running tests nowadays, I use 4" + 0.1' time control. This works out to about 10 seconds per game, which means 3 games per minute for both sides combined. With 32 cores, I can blast through a full ballot2 match within 2 minutes. Even then, there are at most 4 decisive games in a 158-game match. So, I think we really reached the ceiling.

Joost

[gwiesenekker]

Hi Bert,

Interesting. FYI, the latest version of GWD use 'sort moves randomly' as the 'policy network' combined with very aggressive LMR. The problem with very aggressive LMR was that GWD often got 'stuck in the wrong variation', but the 'sort moves randomly' compensates for that. GWD now also checks if it 'gets stuck in a PV', in which case it zaps the TT entries. There are some parameters that control how aggressive the LMR is, I can have GWD draw 100% against Kingsrow, but it then also draws 100% against Flits because it sees that 'all moves lead to a draw'. The default setting loses occasionally from Kingsrow but wins from Flits most of the time.

GW

[Joost Buijs]

There are some parameters that control how aggressive the LMR is, I can have GWD draw 100% against Kingsrow, but it then also draws 100% against Flits because it sees that 'all moves lead to a draw'. The default setting loses occasionally from Kingsrow but wins from Flits most of the time.

This is exactly what I already see here for a long time, when the engine is tuned in such a way that it won't lose from Kingsrow it plays worse against weaker engines. To win from weaker engines you have to play more speculative and aggressive, this fires back at you when you play strong engines like Kingsrow.

[BertTuyt]

Think that Sjende Blyn also uses that principle.
The settings for not losing (or winning) against Kingsrow are different from the settings to win (and not draw) against the weaker engines.
At least this is what I know.
I have no further details.
A pity that apparently there is no knob to turn which generates a +10/20 ELO against Kingsrow and a win towards others.....

Or to repeat some historical words, "Computerdraughts, Game , Set and Match...".

Bert