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Subject: Programmers Question: Hashing and Alpha/Beta bounds

Author: Johannes

Date: 10:10:20 06/06/05


Hello!

While working on my chess engine I've come across two problems which I dont know
how to deal with correctly:

1. After retrieving a hash entry, can I do the following:

    if (tt_flag == UBOUND) beta = MIN(beta, tt_merit);

It has worked for me fine, but is in my opinion theoretically unsound.

2. How to deal with a result from a node where alpha and beta have collided? Ths
happens rarely, but can happen due to altering of bounds because of a hash
entry. What can I do if i want to store the result from such a node? It is
neither a LBOUND nor a UBOUND, right?

I hope some of the more experienced chess programmers can help me with these...

thanks
johannes






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