Author: Bo Persson

Date: 10:51:17 04/14/04

Go up one level in this thread

On April 14, 2004 at 04:57:01, Dann Corbit wrote: >Picking out the hash value and moving the lookup to the end gives a bit better >result: > >/* MTD(f) is an alternative search to pvs */ >int mtdf(int f, int depth) >{ > int beta; > int smallest = -INFINITY; > int greatest = INFINITY; > TranspositionEntry *entry; > > do { > if (f == smallest) > beta = f + 1; > else > beta = f; /* beta is starting with a first best guess */ > f = AlphaBeta(beta - 1, beta, depth); You have a problem right here, if you don't use fail-soft. The returned value will always be either beta or beta-1. > if (f < beta) > greatest = f; > else { > int j; > smallest = f; /* performs a cut-off */ Say you got beta-1 from AlphaBeta. Then you set greatest = beta-1, and try again with a window one single point lower. How long does it take to reach down to the the real upper bound? Bo Persson

- Re: Question for the MTD(f) experts
**Dann Corbit***10:58:58 04/14/04*

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