Do less singular extensions for former PVnode

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 1257637895fe4c93e13375a8b883e2febd972914..c998f20d156bb260ac6aaced49b1835bcfa84ead 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1059,7 +1059,7 @@ moves_loop: // When in check, search starts here
               && (tte->bound() & BOUND_LOWER)
               &&  tte->depth() >= depth - 3)
           {
-              Value singularBeta = ttValue - 3 * depth;
+              Value singularBeta = ttValue - (3 + (ss->ttPv && !PvNode)) * depth;
               Depth singularDepth = (depth - 1) / 2;
 
               ss->excludedMove = move;