Author: blass uri
Date: 12:01:17 08/05/00
Go up one level in this thread
On August 05, 2000 at 12:29:21, Tim Foden wrote: >On August 05, 2000 at 11:37:01, Larry Griffiths wrote: > >>Which Algorithm is considered the best now-adays. >> >>NegaScout? MTD? PVS? Others? I am looking to implement one of the best search >>type algorithms in my program. I would like to get it into the 2000 rated range >>as this has been my lifetime goal. Then, maybe install winboard or something so >>it can compete against other programs to get a rating. >>I dont like MTD as it seems to be complex. > >It is generally possible, and I would say advisable, to implement the search in >small steps. Get one version working before moving on to the more complex >version. > >Thus the searches you mention above, plus plain A-B search, can be ranked in >order of implementaion: >1) Alpha-Beta >2) PV-search >3) NegaScout >4) MTD(f) > >To get from 1) to 2), you need to implement null-window search for non-PV lines. > >To get from 2) to 3), you implement the safe forward pruning near the leaves, or >use razoring if you have extensions. > >You might want to switch 2) and 3) around. > >To get from the 3) to 4) you add the MTD(f) driver on top of the whole thing. > >The thing to remember about MTD(f) (if my memory serves me well) is that I think >it requires a fail-soft version of the underlying search. Fail soft is: when >you detect a cut-off (value >= beta) you return (value). Fail hard is you >return (beta). > >At some point it would be advisable to implement the Null move heuristic. > >All of this is from some hazy memory, so please forgive me if I turn out to be >talking nonsense. :o) > >BTW, I don't necessarily think you need the "best" search algorithm. Just a >good one. I really don't think MTD(f) is a requirement to get a program that is >2000 (or even 2500) rated. I think that alpha beta is enough to get 2000 rating. Computers are very fast and this is the reason that you do not need a good algorithm to get 2000. Uri
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.