Search found 3426 matches

by Sven
Wed Jan 20, 2021 12:56 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Alpha-beta fail soft cut-off issue
Replies: 12
Views: 1621

Re: Alpha-beta fail soft cut-off issue

Regarding the alpha-beta algorithm, the root node is not different from other nodes down the tree, except for the minor fact that you need score and move there while everywhere else you are only interested in the score. So you should use basically the same alpha-beta code at the root, like in: bestS...
by Sven
Wed Jan 20, 2021 8:02 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Evaluation reflections
Replies: 11
Views: 1548

Re: Evaluation reflections

I would focus on getting a strong, bug-free search with a decent effective branching factor that allows to reach depth 10-12 in middle game at least. I don't know for sure whether your engine has already reached that state but I vaguely remember it hasn't. With a strong search and a very simple mate...
by Sven
Tue Jan 19, 2021 10:52 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Tapered Evaluation and MSE (Texel Tuning)
Replies: 220
Views: 15275

Re: Tapered Evaluation and MSE (Texel Tuning)

Parameter tuning without measuring playing strength is nonsense. But it is exactly what Texel tuning is. Tuning by game results is an entirely different method. And I never claimed that Texel tuning was better then tuning through game play. Or in fact that Texel tuning was any good at all. I did no...
by Sven
Tue Jan 19, 2021 10:03 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Tapered Evaluation and MSE (Texel Tuning)
Replies: 220
Views: 15275

Re: Tapered Evaluation and MSE (Texel Tuning)

My point was not that I did not like results, it was that I discarded tuning results due to a significant difference in playing strength. I agree, that is another subject. The translation into elo is important and is measured completely different. Well, it is not the fault of the tuner or the tunin...
by Sven
Tue Jan 19, 2021 9:27 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Tapered Evaluation and MSE (Texel Tuning)
Replies: 220
Views: 15275

Re: Tapered Evaluation and MSE (Texel Tuning)

E.g. when allowing a step size of 8 or even more, I have observed that the pawn MG value jumps away to more than 200cp and both queen values to 1400, 1500 cp and more, leading to weaker play. I have never observed such extremes when using a small step size (1). Basically what you saying is that Tex...
by Sven
Tue Jan 19, 2021 9:25 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Tapered Evaluation and MSE (Texel Tuning)
Replies: 220
Views: 15275

Re: Tapered Evaluation and MSE (Texel Tuning)

Jumbo got a boost of slightly more than 100 Elo points by correctly applying the method. Except that you just told us that you did not correctly apply the method at all. Correctly applying it would be to minimize the MSE. Instead you sabotaged the optimizer to prevent it from finding the minimum MS...
by Sven
Tue Jan 19, 2021 8:26 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Tapered Evaluation and MSE (Texel Tuning)
Replies: 220
Views: 15275

Re: Tapered Evaluation and MSE (Texel Tuning)

E.g. when allowing a step size of 8 or even more, I have observed that the pawn MG value jumps away to more than 200cp and both queen values to 1400, 1500 cp and more, leading to weaker play. I have never observed such extremes when using a small step size (1). Basically what you saying is that Tex...
by Sven
Mon Jan 18, 2021 4:51 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Tapered Evaluation and MSE (Texel Tuning)
Replies: 220
Views: 15275

Re: Tapered Evaluation and MSE (Texel Tuning)

Hi Sven, ... Apart from that, I still believe that extreme outcomes of the tuning process, like those you have shown several times, are caused by the tuning algorithm (including concepts like using higher and/or variable step sizes) and not by the training data. I always got the best results when u...
by Sven
Mon Jan 18, 2021 2:59 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Tapered Evaluation and MSE (Texel Tuning)
Replies: 220
Views: 15275

Re: Tapered Evaluation and MSE (Texel Tuning)

... One would probably get better evaluations (in term of Elo for the engines using them, not in terms of MSE) by testing on games of lower quality. The quicker development of large imbalances would probably be more important than whether an imbalance, once it occurs, would be perfectly mapped on i...
by Sven
Mon Jan 18, 2021 7:56 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Tapered Evaluation and MSE (Texel Tuning)
Replies: 220
Views: 15275

Re: Tapered Evaluation and MSE (Texel Tuning)

But in an absolute sense the fit is very poor: 0.13 is not good at all. Even a constant evaluation would get an mse like that, on a data set with enough draws (48% draws would be enough). Just evaluate every position as 0. Predicted result 0.5. No error on the draws, 0.5 error on the wins and losse...