Use staticEval in null prune condition

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 064df0ca11fafc5b5b100eb23f8a61fd48565e76..97ab5918ae808090ca181aab078e35f15f8399d4 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -731,6 +731,7 @@ namespace {
     if (   !PvNode
         &&  depth >= 2 * ONE_PLY
         &&  eval >= beta
+        && (ss->staticEval >= beta || depth >= 12 * ONE_PLY)
         &&  pos.non_pawn_material(pos.side_to_move()))
     {
         ss->currentMove = MOVE_NULL;