Tweak doubly singular condition (Topo's patch)

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 10a9027b94922cd1982a35b2e42957be22f42564..9b56bd2b08325cf3d871a8a49ec57b352c0c67b6 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1107,8 +1107,8 @@ moves_loop: // When in check, search starts here
 
               // Avoid search explosion by limiting the number of double extensions
               if (   !PvNode
-                  && value < singularBeta - 93
-                  && ss->doubleExtensions < 3)
+                  && value < singularBeta - 75
+                  && ss->doubleExtensions <= 6)
               {
                   extension = 2;
                   noLMRExtension = true;