TT and fifty moves rule
Moderator: Ras
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xr_a_y
- Posts: 1872
- Joined: Sat Nov 25, 2017 2:28 pm
- Location: France
TT and fifty moves rule
Anyone already tried to do some fifty move rule scaling / unscaling when using / inserting in TT ?
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hgm
- Posts: 28353
- Joined: Fri Mar 10, 2006 10:06 am
- Location: Amsterdam
- Full name: H G Muller
Re: TT and fifty moves rule
My experience is that making an engine aware of 50-move draws only costs Elo. If it cannot make progress in 50 moves with a winning evaluation score, it is the evaluation that is at fault and highly overestimating some aspects of the position. Forcing it to do moves it would consider bad evaluation wise just to reset the counter just makes things worse, and might actually cause it to lose drawn positions.
What did help was to have two evaluations, one reluctant to advance Pawns, and one trying to advance those more aggressively. And then switch to the latter when the counter gets above a certain value (like 40 ply). That way it tries two different strategies for making progress, and if neither achieves anything, it had better just accept the draw, rather than deteriorating its position by any standard just to avoid it.
What did help was to have two evaluations, one reluctant to advance Pawns, and one trying to advance those more aggressively. And then switch to the latter when the counter gets above a certain value (like 40 ply). That way it tries two different strategies for making progress, and if neither achieves anything, it had better just accept the draw, rather than deteriorating its position by any standard just to avoid it.