Null Move Pruning Test Results

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Here you can find some experimental test results on Null Move Pruning by varying R on Depth and other features.

Increasing R With Depth

Mark Lefler

One scheme tested by Mark Lefler on 25 October 2007 is as follows:

R=3;
if (side to move has 2 or more pieces) and (depth>7) then R=4;

In a 100 game 1/1 match between Now with and without this change, the change was worth just over 50 Elo. I am now testing against other programs. Followup testing showed only about a 20 Elo gain, with about 100 games against a variety of opponents. Within the error of testing.

See also

• Late Move Reduction Test Results
• Null Move Test-Positions

Forum Posts

• verified null move by Robert Hyatt, CCC, June 21, 2009
• my first cluster test result with R by Daniel Shawul, CCC, January 29, 2010
• value of LMR and null-move by Robert Hyatt, OpenChess Forum, July 12, 2010
• Extended Null-Move Reductions by Alvaro Cardoso, CCC, August 20, 2010

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