Search found 3323 matches

by Sven
Fri Jul 03, 2020 8:28 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: New-ish engine coder, would appreciate if someone could look at my code and point me in the right directions
Replies: 15
Views: 374

Re: New-ish engine coder, would appreciate if someone could look at my code and point me in the right directions

Furthermore, I do not fully understand your code regarding the side to move and the viewpoint of the static evaluation. I see three terms: 1) pos.analysisPlayer, which seems to be the side to move at the root node (but why do you still need to maintain that, after having switched from minimax to neg...
by Sven
Thu Jul 02, 2020 7:58 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: New-ish engine coder, would appreciate if someone could look at my code and point me in the right directions
Replies: 15
Views: 374

Re: New-ish engine coder, would appreciate if someone could look at my code and point me in the right directions

The +abm() must be correct. In Negamax you negate the result of searching a child node where it was the opponent's turn. But in mtdf() you call abm() still at root so there is nothing to negate yet. Your Negamax happens inside of abm() only. Does your static eval return a score from the viewpoint of...
by Sven
Thu Jul 02, 2020 3:03 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: New-ish engine coder, would appreciate if someone could look at my code and point me in the right directions
Replies: 15
Views: 374

Re: New-ish engine coder, would appreciate if someone could look at my code and point me in the right directions

if(m.endPosition.eval > g){ tpMove[pos.hash] = m; pos.bestMove = m; g = m.endPosition.eval; } if(g > a){ a = g; tpMove[pos.hash] = m; pos.bestMove = m; } You only have a PV (and therefore a best move) if its score is within the alpha/beta window. Therefore you should only store the best move if (g ...
by Sven
Thu Jul 02, 2020 2:58 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: New-ish engine coder, would appreciate if someone could look at my code and point me in the right directions
Replies: 15
Views: 374

Re: New-ish engine coder, would appreciate if someone could look at my code and point me in the right directions

jauska wrote:
Thu Jul 02, 2020 12:04 pm
Ras wrote:
Thu Jul 02, 2020 9:34 am
I think the problem is with the handling of the root aspiration window.
Interesting - what do you think I should do with it?
I think that part looks ok, it follows the MTDF algorithm (but see my other post regarding the call of abm()).
by Sven
Thu Jul 02, 2020 2:56 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: New-ish engine coder, would appreciate if someone could look at my code and point me in the right directions
Replies: 15
Views: 374

Re: New-ish engine coder, would appreciate if someone could look at my code and point me in the right directions

In mtdf(), maybe you could try

Code: Select all

currentEstimate = abm(...)
instead of

Code: Select all

currentEstimate = -abm(...)
since you are still at the root ...
by Sven
Wed Jul 01, 2020 5:00 pm
Forum: Computer Chess Club: Tournaments and Matches
Topic: Open Swiss Edition III
Replies: 48
Views: 1744

Re: Open Swiss Edition III

Actually there is no "resign" command in the WB protocol. Engines tell the GUI that they do not continue to play by sending RESULTSTRING {COMMENT} where RESULTSTRING is 1-0, 0-1, or 1/2-1/2, and {COMMENT} is optional. E.g. if the engine plays White and resigns it may send: 0-1 {White resigns} The G...
by Sven
Mon Jun 29, 2020 7:58 am
Forum: Computer Chess Club: Tournaments and Matches
Topic: Open Swiss Edition III
Replies: 48
Views: 1744

Re: Open Swiss Edition III

- Resign is set to -5 for 3 consecutive moves where able. Hi Sergio, what command will be send to the engine in order to let it resign? I would like to implement it (winboard/xboard protocol) Thanks! It may depend on the GUI, but I would assume that it will simply send a "result" command, telling t...
by Sven
Mon Jun 29, 2020 7:32 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Please help with Plankton
Replies: 9
Views: 345

Re: Please help with Plankton

If pruning is disabled when being in check and returning a mate score is restricted to being in check as well then I do not see how this could ever go wrong.
by Sven
Mon Jun 29, 2020 5:33 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: How to correctly implement the null move heuristic when using normal minimax
Replies: 6
Views: 342

Re: How to correctly implement the null move heuristic when using normal minimax

hgm wrote:
Thu Jun 25, 2020 7:51 pm
Be careful, his score is floating point. So beta and beta - 0.01 are not adjacent, as in principle he can also get score beta - 0.005, So his seemingly generous windo setting is a necessity.
That was not my point, it was about correct lower and upper bounds of his null window.