Author: leonid
Date: 18:23:37 08/02/99
Go up one level in this thread
On August 02, 1999 at 11:43:05, Mark Higgins wrote: >On August 01, 1999 at 03:01:38, Ed Schröder wrote: > >>>Posted by Peter McKenzie on July 31, 1999 at 18:06:30: >>> >>>>Here is the position: >>>> >>>>5r1k/6p/1n2Q2p/4p//7P/PP4PK/R1B1q/ w >>> >>>Thanks for posting this position Bob. By the way, here is the position in a >>>more standard format (well, a format that my program can input anyway): >>> >>>5r1k/6p1/1n2Q2p/4p3/8/7P/PP4PK/R1B1q3 w - - >>> >>>LambChop would also suggest that Qxb6 is 'forced' (by Ed's suggestion) >>>after a 1 ply search. Of course, in such positions you should still spend some time >>>searching because they are not certanties by any means. >>> >>>In this particular position, most programs wouldn't be 'burnt' because they >>>would see that Qxb6 is bad after just a few seconds. LambChop (which uses >>>nullmove) discards Qxb6 at depth 7. I believe Crafty has a problem here >>>because it doesn't do any checks in the q-srch. >>> >>>Personally, I'm still uncomfortable with Ed's idea because I'm sure there are >>>many deeper sacrifices that would cause problems. But the trade off might be >>>worth it, who knows? >> >>To detect forced move using no A/B in the first (and second) iteration can >>be used as a base. From there it is not so difficult to find solutions (rules) >>for the trouble makers (exceptions). > >IMHO low-brain fast-searches like DB vs Kasparov have proved it is better to >forget about trouble makers and exceptions and just go for the brute force >approach. Fast and dumb rules. Forget about exceptions they are waste of time. >You spend all clock cycles and programmer time on worrying about exceptions and >then you are full of bugs. > >Ciao > >Mark > > >> >>And because of today's fast computers the exceptions fade away as for >>example the Cray Blitz position is seen by Rebel in 0.5 second. >> >>Ed Schroder I really agree with what was said obove. Now on very quick computers Rebel 10 can see by "brute force" 6 plys ahead in just one or two seconds. Some less superficial revision of the moves but with "fixed horizon" can lead up to 10 or even 12 plys deep. This way of searching the move is best that some other method that care too much about exceptions. Exceptions that take that much space to care about and can produce anyway very suspicious result. Leonid.
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