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Subject: Re: Fritz fixed depth

Author: Andrew Wagner

Date: 18:24:18 05/23/04

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On May 23, 2004 at 21:05:42, BubbleGum1 wrote:

>Whenever I set Fritz to fixed depth of 1 move (2 ply), it frequently finds
>combinations that are deeper than 2 ply.  For example, a standard remove the
>defender combo such as 1...Bxc3 2.dc Nxe4 takes 3 ply, but Fritz finds it at
>fixed depth = 1.  This happens on slightly deeper combos too.
>
>Why is this and how can I make it only search at exactly the specified fixed
>depth?

Pretty much all modern engines would do this. Essentially, when you tell an
engine to search 2 ply, it goes to that depth and tries to find a "quiet"
position. The reason for this is simple. Take for example this position:
[d]rnbqkb1r/pppp1Qpp/5n2/4p3/4P3/8/PPPP1PPP/RNB1KBNR b KQkq -

If you just looked at this position without making any moves, you would say that
white is up a pawn. Now let's say the engine reached this position at the end of
a two ply search. Certainly it shouldn't evaluate this position as +1 for white,
who is about to lose his queen.

So the vast majority of engines will go to that depth, and then look at forcing
moves (usually all captures and sometimes checks), to try to get a position
where less is going on, and then evaluate that position.

Hope this makes sense. Andrew



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