Gradually relax the NMP staticEval check

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index b735281729e78387359866d60d36f20d936e6165..59b1b1f19a84f19dccb8c58b288d53c6944ace9c 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -731,7 +731,7 @@ namespace {
     if (   !PvNode
         &&  depth >= 2 * ONE_PLY
         &&  eval >= beta
-        && (ss->staticEval >= beta || depth >= 12 * ONE_PLY)
+        && (ss->staticEval >= beta - 35 * (depth / ONE_PLY - 6) || depth >= 13 * ONE_PLY)
         &&  pos.non_pawn_material(pos.side_to_move()))
     {
         ss->currentMove = MOVE_NULL;