Author: Georg v. Zimmermann
Date: 09:52:21 09/02/01
Go up one level in this thread
>>- You are not adjusting the bounds, why ? That helps a lot. > >I have thought about this for many times, and actually I am adjusting alpha. >I see however the following problem. When you have window dependent pruning, it >can happen, that a first fail high gives a different score, when researching >with a different window. This adds more inconsistencies. The search may not be >able to reproduce the score with the different window setting, which leaves the >question whom to trust, the hash table or the actual search with the current >window. How do you prune window dependent ? I know that Tiger does that too. But for me it never helped enough to use it instead of simpler stuff. >Also, when adjusting alpha to a lower bound value, this value is >actually outside of the window. So, say the value was actually exact, one ends >up without a PV. Also, it is not really clear, what sort of node this is. It was >a lower bound earlier, now it an upper bound that is inside of the original >search window, but outside of the window with the adjusted bounds. > I don't follow. Only if the score was from a fail high I adjust alpha to be at least as good as the hashscore. It must be within the window since if it was > beta the hash lookup would have even produced a fail high. Georg
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