Tune null move pruning

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 7875f0345f3d9d9f4c0268b7d613689f7cd85c7e..a4b2ef348566eb4b62d462e0e8c63b62c1343eae 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -734,7 +734,7 @@ namespace {
     // Step 9. Null move search with verification search (~40 Elo)
     if (   !PvNode
         && (ss-1)->currentMove != MOVE_NULL
-        && (ss-1)->statScore < 30000
+        && (ss-1)->statScore < 22500
         &&  eval >= beta
         &&  ss->staticEval >= beta - 36 * depth / ONE_PLY + 225
         && !ss->excludedMove