Author: Uri Blass
Date: 06:17:51 10/02/01
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On October 02, 2001 at 08:38:01, Steve Maughan wrote: >Gordon, > >Some programs do a 'thorough' static analysis of the position before they start >to search. They then assign values for a piece being on any one of the squares. > This is root node processing or pre-processing. The advantage is speed of >evaluation but the (big) dissadvantage is that what seems like a good idea at >the root may not be so good at the tip of a search e.g. rook on 7th when King is >on 8th is good but when the king starts to advance up the board the preprocessor > still thinks that the rook on the 7th is good. Moreover, as machines get >faster and search deeper the problem gets worse since the tips are further away >from the root. > >The alternative is tip evaluation which is slower but *MUCH* more accurate when >done well. The famous pre-processors are early Fritz versions, Rex chess, >Travel Champion, Novag Constellation and anything that claims to do >1.5 million >nodes / sec on a single processor e.g. Little Goliath. Junior was always >considered to be a preprocessor but I seriously doubt it now as the evaluation >is usually rock solid between moves and the scores seem to contain extensive >king safety elements. Junior was not considered to be a preprocessor. It is known to have a stable evaluation from the first commercial version(Junior4.6) Amir admitted that Junior6 did some preprocessing but he said that it is a problem that he is going to correct and he corrected it in Junior7. Uri
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