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Jorge Pichard

Joined: 09 Mar 2006
Posts: 2558

Post subject: Re: What engine can see the best move Bf8+!    Posted: Wed Apr 11, 2012 8:21 am

BubbaTough wrote:
pichy wrote:
 Dan Andersson wrote: I'm not claiming human superiority but a surprisingly large number of humans would play the correct move even in a bullet game MvH Dan Andersson

I agree with you, if GM Nakamura has this position he would be making a move every second and find the correct move

I consider that quite plausible. The basic winning idea is not that hard to find, and there really isn't anything else to try. Even lesser grandmasters are darn good calculators when there is only one forcing line to look at and there are no other good candidate moves. I suspect most strong players would play the right moves even at fairly rapid time controls. The only thing to calculate is whether the queen can pull some trick after 4. Bf6, but since there is no other move that really gives white a chance, many would just play the moves to get to this position, and then calculate the rest.

-Sam

Will your next version of Hannibal be able to find it, by fixing the Null Moves heuristic
?

Null Move Heuristic
As mentioned above in the section on Internal iterative Deepening, there is a minimum search tree that can be obtained simply by using conventional alpha-beta pruning methods. However, this limit is not an absolute limit, and can be avoided if one is willing to make one or two sacrifices in search accuracy. One method used to great effect in all strong modern programs is that of NULL move pruning. ColChess does not use this method, but Beowulf does.

Null move pruning is a clever, and relatively recent method first proposed by Donninger (1993). The algorithm is simple, and in fact simply codes a concept that humans have been using for many years without knowing it.

Quiescence Search
The problem with abruptly stopping a search at a fixed depth is something called the 'horizon effect'. It might be that you have just captured an opponent's pawn at depth 0, then you return that score being justifiably proud. However, if you had searched another ply deeper you would have seen that the opponent could recapture your queen!

Full width search is not much different to the original search at depth>0, generating all the possible available moves and testing to see which one is the best.
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Subject Author Date/Time
Jorge Pichard Tue Apr 10, 2012 6:51 am
Robert Houdart Tue Apr 10, 2012 9:18 am
Jorge Pichard Tue Apr 10, 2012 11:16 pm
om prakash Thu Apr 12, 2012 6:46 pm
Dan Andersson Wed Apr 11, 2012 1:07 am
Jorge Pichard Wed Apr 11, 2012 1:52 am
Sam Hamilton Wed Apr 11, 2012 3:37 am
Re: What engine can see the best move Bf8+! Jorge Pichard Wed Apr 11, 2012 8:21 am
Sam Hamilton Wed Apr 11, 2012 12:47 pm
Jorge Pichard Wed Apr 11, 2012 5:10 pm
Sam Hamilton Thu Apr 12, 2012 12:44 am
Jorge Pichard Thu Apr 12, 2012 1:33 am
kgburcham Wed Apr 11, 2012 3:07 am
Ernest Bonnem Wed Apr 11, 2012 2:49 pm
Uri Zlatnik Thu Apr 12, 2012 1:56 am
Jorge Pichard Thu Apr 12, 2012 2:12 am
Ernest Bonnem Thu Apr 12, 2012 7:54 am
Uri Zlatnik Thu Apr 12, 2012 8:05 am
Jorge Pichard Thu Apr 12, 2012 12:20 pm
Uri Zlatnik Thu Apr 12, 2012 1:24 pm
Jorge Pichard Thu Apr 12, 2012 2:58 pm
Matthew R. Brades Thu Apr 12, 2012 5:05 pm
Jorge Pichard Thu Apr 12, 2012 5:15 pm
Martin Hertz Thu Apr 12, 2012 5:58 pm
Tano-Urayoan Russi Roman Thu Apr 12, 2012 8:14 pm
Jorge Pichard Thu Apr 12, 2012 9:45 pm
Jorge Pichard Thu Apr 12, 2012 9:45 pm
Graham Banks Thu Apr 12, 2012 9:53 pm
Marek Kwiatkowski Fri Apr 13, 2012 10:14 am
Gary Fri Apr 13, 2012 2:08 pm
Marek Kwiatkowski Fri Apr 13, 2012 7:17 pm
Gary Sat Apr 14, 2012 2:10 am
Marek Kwiatkowski Fri Apr 13, 2012 3:28 pm
Jorge Pichard Sat Apr 14, 2012 1:39 am
Lucas Braesch Sat Apr 14, 2012 6:41 am
Jorge Pichard Sat Apr 14, 2012 7:19 am
Jorge Pichard Sat Apr 14, 2012 6:44 pm
Jorge Pichard Sun Apr 22, 2012 11:33 pm
Louis Zulli Tue Apr 10, 2012 10:21 am
Andrea Sorcinelli Tue Apr 10, 2012 11:41 am
Zlatin Stoyanov Tue Apr 10, 2012 12:13 pm
Jorge Pichard Tue Apr 10, 2012 12:52 pm
Jorge Pichard Tue Apr 10, 2012 7:05 pm
Louis Zulli Tue Apr 10, 2012 8:03 pm
Jesús Muñoz Wed Apr 11, 2012 11:07 am
Gary Wed Apr 11, 2012 12:16 pm
Jorge Pichard Thu Apr 12, 2012 12:10 am
Jorge Pichard Thu Apr 12, 2012 4:54 pm
Gary Fri Apr 13, 2012 3:20 pm
Jorge Pichard Sat Apr 14, 2012 12:57 am
Gary Sat Apr 14, 2012 2:12 am
Jorge Pichard Mon Apr 23, 2012 9:06 pm
Jorge Pichard Thu Apr 26, 2012 11:04 am

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