Search found 132 matches

by abulmo2
Thu Jul 18, 2019 12:03 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Understanding first rank attack state generation
Replies: 8
Views: 195

Re: Understanding first rank attack state generation

I I understood most part of the code except this lines (appearing twice in generate_rank_attack): if ((o & b) == b) break; What is the use of the above if loop conditional? Many Thanks, Kalyan The purpose of this code is to generate an attack mask containing empty squares and the first occupied squ...
by abulmo2
Mon Jul 01, 2019 9:41 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Exchange
Replies: 15
Views: 533

Re: Exchange

This is scary. Does others engines exhibit such lower EG values ? For Amoeba, pawn, rook, bishop pair and material imbalance have significantly stronger values during the endgame phase. knight and bishop keep about the same value and the queen is slightly stronger. However, Amoeba's evaluation func...
by abulmo2
Sun Jun 02, 2019 2:48 pm
Forum: Computer Chess Club: Tournaments and Matches
Topic: CCRL 40/40, 40/4 and FRC lists updated (1st June 2019)
Replies: 3
Views: 613

Re: CCRL 40/40, 40/4 and FRC lists updated (1st June 2019)

The latest CCRL Rating Lists and Statistics are available for viewing from the following links : http://ccrl.chessdom.com/ccrl/404 (40/4) 40/4 testing since the last update report has included (thanks to Gabor and Tirsa): Amoeba 3.0 64-bit Thank you for running all those games with Amoeba. I hope t...
by abulmo2
Fri May 24, 2019 1:24 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: QSearch perft
Replies: 24
Views: 2415

Re: QSearch perft

These are the counts I get per move at depth 4, maybe it helps. g2h3: 381 d5e6: 436 e5g6: 495 e5d7: 642 e5f7: 475 e2a6: 343 f3h3: 397 f3f6: 521 Maybe somebody else can verify these numbers. I think the difference is due to the fact that you don't generate check-evasions, because check-evasions will...
by abulmo2
Sat May 11, 2019 10:12 am
Forum: Computer Chess Club: General Topics
Topic: Opposite Color Bishop Endgames
Replies: 43
Views: 2964

Re: Opposite Color Bishop Endgames

The following 8-piece endgame just arose in a Raubfisch X40a3-Cfish match: [d]4b3/8/6k1/6p1/p6p/K3B1P1/8/8 w 01 Virtually all humans immediately see that this is a draw. A simple variation of the above position: [d]4b3/8/2p3k1/2K3p1/7p/4B1P1/8/8 w - - 0 1 Here it is a black win. I just move a pawn ...
by abulmo2
Fri May 10, 2019 10:31 pm
Forum: Computer Chess Club: General Topics
Topic: Opposite Color Bishop Endgames
Replies: 43
Views: 2964

Re: Opposite Color Bishop Endgames

One should remember that the design goal of engines is in general not to be good at chess, but just to have a high Elo. If worse programs score better in games, it is preferred to make them worse. I have some trouble to understand you, to be good at chess IS to have a high Elo . In the case of oppo...
by abulmo2
Fri May 10, 2019 5:59 am
Forum: Computer Chess Club: General Topics
Topic: Opposite Color Bishop Endgames
Replies: 43
Views: 2964

Re: Opposite Color Bishop Endgames

In Amoeba the opposite bishop code made my program weaker by a few Elo.
by abulmo2
Mon Apr 29, 2019 11:32 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Near-random movers
Replies: 21
Views: 4302

Re: Near-random movers

Once I counted when and how games terminate in case of
- a random mover:
Image
- a mate-in-1 mover:
Image
by abulmo2
Sat Apr 27, 2019 3:50 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Prefetch and Threading
Replies: 4
Views: 616

Re: Prefetch and Threading

The Prefetch() instruction can be used to speed up the read operation for hash table probes. My tests indicate a speed improvement for one CPU using Prefetch(), but increasing threads decrease the effectiveness of Prefetch(). What is happening? I do not know what is happening, but I do observe a si...
by abulmo2
Sat Apr 27, 2019 3:24 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: calculating seldepth
Replies: 2
Views: 399

Re: calculating seldepth

One aspect of the uci protocol I am not 100% sure about is seldepth. How do you calculate this? Is it the maximum depth qsearch has reached? In Amoeba, I compute it as the maximum depth reached in qsearch. Side question: should the depth we send in info string should be the iterative deepening dept...