Search found 1135 matches

by Ras
Sat Oct 31, 2020 1:16 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Rustic vs. Shallow Blue: one of us is weird somehow
Replies: 18
Views: 397

Re: Rustic vs. Shallow Blue: one of us is weird somehow

When alpha improves, the current move is saved as best_move, which is exists outside the move loop. If alpha doesn't improve further, best_move doesn't change. Ah OK, so that's a bit of an indirect implementation because usually, the node's alpha itself is increased (and mutable), and the compariso...
by Ras
Sat Oct 31, 2020 12:42 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: c-chess-cli
Replies: 62
Views: 19781

Re: c-chess-cli

Round-robin is available now. Thanks for the update! I like it more every day, really a no-nonsense tool and no dependency hell. If I may suggest new features: 1) Adjustable log level. I'd like to choose between full log, or errors only. In the latter case, ideally only generating log files upon th...
by Ras
Fri Oct 30, 2020 11:50 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Rustic vs. Shallow Blue: one of us is weird somehow
Replies: 18
Views: 397

Re: Rustic vs. Shallow Blue: one of us is weird somehow

It is just alpha that improves inside the move loop, so "alpha != start_alpha" (after the move loop) will be true if alpha improves even once. Exactly. But the moves after the move that has increased alpha, but which don't improve alpha furthermore, will also run into this condition while they shou...
by Ras
Fri Oct 30, 2020 9:45 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Make engine stop repeating moves in a clearly won position
Replies: 35
Views: 875

Re: Make engine stop repeating moves in a clearly won position

Yeah! :) Btw., remember that the draw checking should only happen on fully legal moves. While the history repeat could not happen on illegal ones, the "insufficient material" check could evaluate to "true" if some capture leads to insufficient material, but the capture is not actually possible becau...
by Ras
Fri Oct 30, 2020 9:43 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Rustic vs. Shallow Blue: one of us is weird somehow
Replies: 18
Views: 397

Re: Rustic vs. Shallow Blue: one of us is weird somehow

mvanthoor wrote:
Fri Oct 30, 2020 8:28 pm
This works.
What happens if one move improves start_alpha, and another one improves alpha even further? Or, what happens if another move doesn't improve alpha further, then alpha would still be different from start_alpha after the first alpha raising move?
by Ras
Wed Oct 28, 2020 6:52 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Make engine stop repeating moves in a clearly won position
Replies: 35
Views: 875

Re: Make engine stop repeating moves in a clearly won position

So you mean to skip the move ("continue" the loop as you do if make() returns that the move is not legal) No, I meant that you usually have something like this in your node loop: for all moves in the node: make_move t = recursion(...) unmake_move if (t > alpha) do_something if (t >= beta) do_cutoff...
by Ras
Wed Oct 28, 2020 3:30 pm
Forum: Computer Chess Club: General Topics
Topic: Question to Shut Ctf Down posters
Replies: 75
Views: 2190

Re: Question to Shut Ctf Down posters

Guenther wrote:
Wed Oct 28, 2020 1:06 pm
Well, but he voted for shutdown in this 'survey'.
So did I, but since it looks like the shutdown poll is being ignored, the backup option is implementing SHID as CTF moderator team, which in turn requires three mods agreeing on that policy - and of course, them being elected in the CTF election.
by Ras
Wed Oct 28, 2020 3:12 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Make engine stop repeating moves in a clearly won position
Replies: 35
Views: 875

Re: Make engine stop repeating moves in a clearly won position

PS: If I put the call to is_repetition directly after make() (in the move loop), the engine instantly returns with minus infinity, That's probably because you shouldn't return 0 as value from the loop at that point - only skip the usual recursive evaluation and use 0 as "value for this move". Means...
by Ras
Tue Oct 27, 2020 10:31 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Make engine stop repeating moves in a clearly won position
Replies: 35
Views: 875

Re: Make engine stop repeating moves in a clearly won position

mar wrote:
Tue Oct 27, 2020 10:05 pm
It should be obvious that captures are irreversible and thus reset move history, but somehow you didn't quote this back.
Indeed, I overlooked that, and you're right. Do you have numbers how often the repetition detection in QS actually does detect a repetition? Because I think it should be about 0.
by Ras
Tue Oct 27, 2020 9:45 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Make engine stop repeating moves in a clearly won position
Replies: 35
Views: 875

Re: Make engine stop repeating moves in a clearly won position

as for performance, I don't think that probing a rep hash/iterating history list in each qs node would be something you could even measure. Given that by far most nodes are QS nodes, and that you can have positions where you don't have irreversible moves for quite some time, I'm not sure whether it...