DaveKitt wrote:Nope, don't remember when, could have been NYC. The whole 0x88 is pretty obvious. In fact, another big benefit is that you could take the difference of two sqs and use that to look into a table to see the legal piece types that could be attackers. Having bit 3 cleared prevented wrap arounds on this look up. Hence, for most my programs the basic capture routine iterated from largest to smallest captured piece, using smallest to largest capturing piece, taking the difference of the sqs, looking up in att_table and seeing if nz, if nz, then if & with attacker type bit nz then just had to check if slider and had path clear. Of course, w and b pawns had different type bits. Made for a decently fast and ordered capture search.
There's also the nicety of asking "are these on the same diagonal?" and such. But in the world of bitboards, it's all moot of course.
DaveKitt wrote:Fern, ah yes, but my recurring virus has been trying to improve my sorely lacking golf swing, which has many advantages over programming in I can pursue that activity outdoors! However, I must say all this posting has gotten me curious enough to take a look at some of the open sources out there. Looked at Fruit 2.1 which is much more in my style of programming - i.e. limited commenting, very 'C' like, and same flavor of data representations. Crafty or Stockfish are probably better starting pts as they use bitboards. At this point though, it is enough to just stare in fascination as search depths of 20+ plies are achieved in midgame positions in a minute or less.
Hi Dave,
Nice to meet you again, now here in virtual life. Last time was in Amsterdam 1985 you playing in the commercial group with Blitzmonster, Frans Morsch and me playing in the amateur group having frequent attacks of jealousy because we also wanted to be there where the big boys were and the real thing happened.
Anno 2012 I am now the chairman of the CCAA (Computer Chess Addicted Anonymous) an organization specialized helping poor chess programmer addicts to become totally dry and to stay clean. We offer various training programs (among them golf therapy ) in combination with detoxification meds to fight the CC virus that keeps mutating itself on an AI base and as recent scientific research has discovered is linked to the LMR-virus that mutated with the AB-virus and the new variation has the potential to reach addiction depths of 50 plies and beyond.
Kidding aside, if the virus takes over again anyway take Stockfish as a base, it's close to the current top and make us happy to add your own unique ideas to it and shake the current top-5.
Ed, too funny! I need to be careful or I'll require membership in CCAA. Your programs did very well. I think it was just real luck and good timing that I got in so early with 'the big boys'.
Daniel,
Yep, that was one of my all time favorites. Especially since during the game the commentary early on was that WChess was in lots of trouble and around move 17 I'm saying I think it will sac the 'd' pawn realizing the bind that is developing and Deep Blue team is saying no way, nothing showing up on search results to show sac was playable. Then on move 21 WChess play d5! Many of journalists were all excited about this result of a micro drawing w/Deep Blue and I was very satisfied. Of course, Deep Blue getting crushed the next day by another micro sort of took the luster off the result
When playing in these computer vs computer tournaments against some of the monsters playing on supercomputers or special hw, it was horribly difficult to score. Your program could play and play keeping things together then BAM, something just out their tactical search would be uncovered and basically game over.
DaveKitt wrote:Daniel,
Yep, that was one of my all time favorites. Especially since during the game the commentary early on was that WChess was in lots of trouble and around move 17 I'm saying I think it will sac the 'd' pawn realizing the bind that is developing and Deep Blue team is saying no way, nothing showing up on search results to show sac was playable. Then on move 21 WChess play d5! Many of journalists were all excited about this result of a micro drawing w/Deep Blue and I was very satisfied. Of course, Deep Blue getting crushed the next day by another micro sort of took the luster off the result
When playing in these computer vs computer tournaments against some of the monsters playing on supercomputers or special hw, it was horribly difficult to score. Your program could play and play keeping things together then BAM, something just out their tactical search would be uncovered and basically game over.
Actually that game is annotated in Powerchess by the Powerchess queen. Interesting game, even deepblue was rattled by that sexy women.
You don't know me but I just wanted to express my gratitude for your early work
in computer chess programming. I can't begin to say how many hours of pleasure
your program in the Novag Super Constellation gave me. I still have it and it still
works!!
DaveKitt wrote:
Just for the record, I did have some collaborators over the years besides Don and Larry as mentioned above. I think Hal Bogner was first 'chess contributor', he helped with testing and input for evaluation ideas back when I worked in Van Nuys. After Hal, Scott McDonald contributed chess knowledge and reviewed literally hundreds of autotest games looking for weaknesses and improvements. When I moved to Mobile, Al, James Parker worked with me off and on for several years. James is s very bright fellow and wrote a Shogi program for Novag. He also contributed to the chess efforts and the Chinese Chess program as I recall. There were also a number of ideas adopted as result of conversations with various programmers at the computer chess tournaments I attended.
Dave,
one question about James Parker. He is mentioned in the WCCC 1995 booklet as co-author of Ferret.
It that true? Or should he have mentioned as co-author of WChess?
However, I must say all this posting has gotten me curious enough to take a look at some of the open sources out there. Looked at Fruit 2.1 which is much more in my style of programming - i.e. limited commenting, very 'C' like, and same flavor of data representations. Crafty or Stockfish are probably better starting pts as they use bitboards. At this point though, it is enough to just stare in fascination as search depths of 20+ plies are achieved in midgame positions in a minute or less.
) in combination with detoxification meds to fight the CC virus that keeps mutating itself on an AI base and as recent scientific research has discovered is linked to the LMR-virus that mutated with the AB-virus and the new variation has the potential to reach addiction depths of 50 plies and beyond.
