Author: Robert Hyatt
Date: 10:47:03 09/25/00
Go up one level in this thread
On September 25, 2000 at 11:41:18, David Rasmussen wrote:
>Am I the only one who
>
>a) thinks that the kind of null move pruning that is done in Hyatt's Crafty is
>the reverse of what Ernst Heinz concludes in his paper about ANMP
I hope not. IE here is my code for that:
null_depth=(depth > 6*INCPLY) ? 4*INCPLY : 3*INCPLY;
Which says if the remaining depth is more than 6 plies, use R=3, while
if the remaining depth is <= 6 plies, use R=2.
The "6" is pretty arbitrary. I ran a lot of tests before choosing this
number. Ernst found the same number totally independently of me, although I
think we did use some "common tests" (ie WAC, etc) without knowing what the
other was doing.
>
>b) experiences better performance (less nodes, less time etc.) with Hyatt's
>scheme than with Ernst's scheme.
>
>I.E. When I do
> if (depth>6)
> R=2;
> else
> R=3;
>I get the best results.
>Why?
What is depth for you? Current ply? Or plies remaining? For me it is
plies remaining before dropping into q-search, which means I am doing the
same thing as Ernst, basically. Your code is the exact opposite of what we
are doing, assuming 'depth' means plies remaining and not depth from root of
the tree.
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