Author: James Swafford
Date: 03:27:43 11/29/01
Go up one level in this thread
On November 29, 2001 at 01:10:25, Tony Werten wrote: >On November 28, 2001 at 20:16:45, James Swafford wrote: > >>On November 28, 2001 at 13:41:26, Tony Werten wrote: >> >>>On November 28, 2001 at 13:05:23, Derek Mauro wrote: >>> >>>>When I call search(), I'm supposed to be using -INFINITY as alpha and INFINITY >>>>as beta. Anyway, I've never used INFINITY in a program before. How do I use >>>>INFINIITY? Do I need to include a special library or just define it as the >>>>largest possible int value, or something else? >>> >>>Just use the value you use for checkmate (without depth correction ) That's >>>infinite enough. >>> >>>Tony >> >>The absolute value for INFINITY for me is a little bigger than >>CHECKMATE, so that the condition if (score > alpha) is true >>even when the first move gets a score -CHECKMATE and alpha is >>-INFINITY. Nothing gets backed up to the pv unless that condition >>is met. (Of course you're in serious trouble in that case. :) > >You're already in trouble if a move scores -checkmate. If it happens at ply 0 >than the game is finished, if it is ply 1 or more the score should be >-checkmate+1 (or more ) That's true, assuming he will use depth correction. (I do.) The point is to ensure the first move will get placed in the pv. If the range of valid scores is in the closed interval [-CM .. CM], why make assumptions when it's easier to move INFINITY outside that range? A silly argument to be sure... -- James > >Tony > >> >> >>-- >>James
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.