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Subject: Re: Mobility Tables - what are they?

Author: Ed Trice

Date: 17:34:17 04/30/04

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Slightly off topic...

I have also been toying with the concept of Frequency Filtering. I track the
number of times the same piece moves throughout the first 30 plies of the game.
So Nb1-c3-d5-e3 would have the QN tagged with +4 in that given position. I do
this for everything excpet the kings and pawns.

Depending on the move count of the game, either a penalty or a bonus is applied.
For example, at move 2, if the Queen frequency is non-zero, there is a 15 point
penalty. It is enough to discourage 1. e4 e5 Qh5 from being searched too deep in
the game tree.

If on move 6 a Bishop has moved 3 times, that is also hit with a penalty.

If a knight has a frequency of movement of 0, that is likewise discouraged.

In the game of Gothic Chess, I have reduced the game tree by 40% using this
concept, although the Archbishop and Chancellor pieces are most likely the
reason why this is so effective.



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