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Subject: Re: Programmers: beginner tree search questions

Author: Edward Seid

Date: 14:03:46 09/30/03

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On September 30, 2003 at 16:49:41, Gian-Carlo Pascutto wrote:

>On September 30, 2003 at 16:34:37, Edward Seid wrote:
>
>>Question 1:
>>I've been reading the literature about alpha-beta pruning.  Normally, the
>>initial call to alpha-beta is with alpha = -infinity and beta = +infinity.  If
>>one wanted to do a tree search all the way to the terminal nodes, where the
>>score would be either -9999 or 0 or +9999, would it make sense to set alpha =
>>-9999 and beta = +9999 in the first call to alpha-beta?
>
>I'd use -10000 and +10000, but it probably makes no difference.

In the example where the terminal nodes are either -9999 or zero or +9999, it
does make a difference.  Setting alpha/beta to +/-10000 performs the same as
+/-infinity.  If using +/-9999, then it's possible for the score to equal either
alpha or beta.  Shouldn't that result in faster cutoffs or is my logic wrong?

• Re: Programmers: beginner tree search questions Russell Reagan 14:19:52 09/30/03
  • Re: Programmers: beginner tree search questions Patrick N 15:06:52 09/30/03
  • Re: Programmers: beginner tree search questions Gian-Carlo Pascutto 15:05:50 09/30/03
    • Re: Programmers: beginner tree search questions: My conclusion Edward Seid 22:10:12 09/30/03
      • Re: Programmers: beginner tree search questions: My conclusion Bo Persson 01:34:57 10/01/03
    • Re: Programmers: beginner tree search questions Uri Blass 16:19:26 09/30/03

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