Author: Pete R.
Date: 11:39:18 02/02/00
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I ran both Fritz 5.32 and Crafty 17.7 to 16 ply, and while they agree that Bg5 is best they do not eval a clear win until you feed it to them. If you give them 1. Bg5 Nc5, Crafty finds the Bxd8 Nxa4 O-O-O +- continuation before Fritz does. But neither one of them sees this from the root position. This is yet another example of a position where the search depth is sufficient to cover the solution, but the programs don't see it until you give them a hint. Specifically the position after 1. Bg5 Nc5 takes 12 ply for both Crafty and Fritz to see the win, but since I ran them both to 16 ply, they should have seen the win from 2-ply back, but didn't. Of the programs I have, Hiarcs 7.32 is fastest to see the win (and eval it as such) in the position after Bg5 Nc5, but is as blind as the others to see this winning line from the root. In theory alpha-beta should cover this, i.e. a 16 ply search should find something that a 12 ply search finds from a position 2 ply down the road, but reality is different. This is another example where a bunch of shorter searches backsolved would be superior to a deep search from the root.
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