Author: Robert Hyatt
Date: 07:17:08 09/07/04
Go up one level in this thread
On September 05, 2004 at 23:16:30, Michael Henderson wrote: >On September 05, 2004 at 17:32:57, Alessandro Scotti wrote: > >>On September 05, 2004 at 03:24:56, Michael Henderson wrote: >> >>>How was 6...Bxg1 possibly stored as the best move at that node? Once you search >>>all the moves, to whatever depth, the best move Qh4# is stored along with score >>>returned. Is this something characteristic of MTD(f)? >> >>It was stored there because it was explored deeper. The search returned Qh4# as >>the best move, but then it wasn't stored in the hash table because the >>replacement policy (deeper is better) preferred the entry that was already >>there. > >In MTD(f) all searches use null window? If that is true how is it possible to >get an exact score/move stored in hash table? On the last "2 cycles" the same PV will fail low and high. Since you need to store both bounds, you can always keep a "best move" even when you fail low (the best move comes from the next-to last or last search that failed high here...) There are other ways to do the same thing, all taking advantage of the same basic property of the mtd(f) search...
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