Search found 289 matches

by zenpawn
Fri Aug 26, 2016 10:28 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: On-line engine blitz tourney August
Replies: 45
Views: 5088

Re: On-line engine blitz tourney August

How does this work? Any rating restrictions? Is there a way to watch?

Thanks,
-Erin
by zenpawn
Wed Aug 24, 2016 11:20 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: transposition table pseudocode
Replies: 14
Views: 2195

Re: transposition table pseudocode

Nice to read that. So was the bug related to transposition table handling or not? You seemed to have excluded that it wasn't. Yes, related. It's a bit embarrassing, but here goes... At some point, I decided it was clever to use the fact a move was the only one available to save its eval before the ...
by zenpawn
Wed Aug 24, 2016 10:21 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: transposition table pseudocode
Replies: 14
Views: 2195

Re: transposition table pseudocode

Thank you all for your validations and suggestions. It helped me to stop focusing on these parts and find the silly bug in code not shown here. Hopefully the initial pseudocode, with the followup correction and your tweaks, will serve as a good starting place for the next intrepid chess programmer a...
by zenpawn
Tue Aug 23, 2016 8:53 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: transposition table pseudocode
Replies: 14
Views: 2195

Re: transposition table pseudocode

So, it seems there are no major faux pas. Of course, as you all know, that's both good and bad news when you're trying to track down an elusive bug! :)
by zenpawn
Tue Aug 23, 2016 8:49 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: transposition table pseudocode
Replies: 14
Views: 2195

Re: transposition table pseudocode

- Don't store evaluations in the hash table, you'll pollute what could be useful searches with information useful only to the qsearch. Instead, use a separate eval hash table. To clarify, you're referring to the beta cutoff in the quiesce section, right? That's how I took it this morning, but want ...
by zenpawn
Tue Aug 23, 2016 10:21 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: transposition table pseudocode
Replies: 14
Views: 2195

Re: transposition table pseudocode

- Null move should store at original depth, not at depth - R or zero. This maximises cutoff potential, saving even a nullmove search. Thanks. I've had it that way originally, but this bug has me locking everything down, since missing a hit is likely not the cause. - Don't store evaluations in the h...
by zenpawn
Tue Aug 23, 2016 10:16 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: transposition table pseudocode
Replies: 14
Views: 2195

Re: transposition table pseudocode

exact entries of sufficient depth can always be returned, they don't have to be inside the bounds - if you want to clamp to alpha/beta before returning that's fine (fail hard) or you can return it as is (fail soft) This was a recent addition to be conservative. I also read an old post wherein Rober...
by zenpawn
Mon Aug 22, 2016 11:51 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: transposition table pseudocode
Replies: 14
Views: 2195

transposition table pseudocode

I've been experiencing a strange TT-related bug lately (doesn't happen when it's disabled). My engine will play an OK game for a while before going bonkers and just ditching its queen for no reason. It might have been there before to a lesser degree, but I'm really noticing it now that I'm using the...
by zenpawn
Sat Aug 20, 2016 10:58 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: "moveerror" in Arena debug log
Replies: 2
Views: 547

Re: "moveerror" in Arena debug log

In this case, the offending engine is mine. It's a strange message though as I wouldn't expect Arena (or Winboard) to be trying to parse the moves in the thinking output. Also, the moves before and after the line look fine, so it might not be displaying what it thinks is wrong, just the error instead.