Search found 18990 matches

by hgm
Fri Jan 15, 2021 4:08 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: How to efficiently generate individual moves from bitmasks of pieces?
Replies: 4
Views: 54

Re: How to efficiently generate individual moves from bitmasks of pieces?

Well, I have never used bitboards, but I don't see how doing all Knights at once could ever be better. For a single Knight the set of target squares can be a simple lookup in a 64-entry table indexed by square number. I already don't see how you could get the set of all squares attacked by a Knight ...
by hgm
Fri Jan 15, 2021 2:38 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Tapered Evaluation and MSE (Texel Tuning)
Replies: 84
Views: 1717

Re: Tapered Evaluation and MSE (Texel Tuning)

I thought about that this morning too, that it could explain it as well. Another problem might be that it looks like you haven’t computed the K from your test data (see code below). That means that the mapping between centipawn scores and probabilities might be completely off. Calculate the K Value...
by hgm
Fri Jan 15, 2021 11:58 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Tapered Evaluation and MSE (Texel Tuning)
Replies: 84
Views: 1717

Re: Tapered Evaluation and MSE (Texel Tuning)

The reported mse are suspect. I suppose you are calculating the error as the difference between the eval given in the EPD and what your function calculates. But if you use a constant, the minimum of that should occur when that constant is the average evaluation of all your positions, and grow as the...
by hgm
Thu Jan 14, 2021 6:23 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Tapered Evaluation and MSE (Texel Tuning)
Replies: 84
Views: 1717

Re: Tapered Evaluation and MSE (Texel Tuning)

So the conclusion is that the set of positions sucks, and contains virtually no information on the mg piece values?
by hgm
Thu Jan 14, 2021 5:46 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Tapered Evaluation and MSE (Texel Tuning)
Replies: 84
Views: 1717

Re: Tapered Evaluation and MSE (Texel Tuning)

If you doubt your code / algorithm, just test it on a simple case with a known outcome. E.g. let it run on a set of 10 positions: K + P,N,B,R or Q vs Q, which you evaluate as 100, 300, 350, 500 and 975, and a FIDE setup from which you deleted a black P,N,B,R or Q, eveluated as 80, 325, 325, 475 and ...
by hgm
Thu Jan 14, 2021 11:07 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Tapered Evaluation and MSE (Texel Tuning)
Replies: 84
Views: 1717

Re: Tapered Evaluation and MSE (Texel Tuning)

I understand, good point! Especially if the pawn value is an anchor the phase 24 does not provide any information the algorithm can learn from. It would never update anything for n,b,r or q. That reduces the training sample by 15% already. So, it would be ideal to use positions that include an imba...
by hgm
Thu Jan 14, 2021 9:50 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Tapered Evaluation and MSE (Texel Tuning)
Replies: 84
Views: 1717

Re: Tapered Evaluation and MSE (Texel Tuning)

If you belief the tuning algorithm to work properly (i.e. indeed minimize the rms error on the total set), the only explanation for non-sensical values of the parameters producing the minimum error is that your test set doesn't contain enough prositions that punish the use of non-sensical values, in...
by hgm
Wed Jan 13, 2021 10:09 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Tapered Evaluation and MSE (Texel Tuning)
Replies: 84
Views: 1717

Re: Tapered Evaluation and MSE (Texel Tuning)

But we talk about why the tuner will diverge the mg an eg value while keeping the average of both constant. That much I understood. But doing this should greatly drive up the rms error, agreed? Because keeping the average constant will prevent any effect on the prediction for those positions that h...