Don't split if reduced depth is below min_split_depth

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 0087cdc029d0f307f11eaf0f74076c29b8638fcd..be6e360af337c5b4e527b99c67a58fc40ee8d659 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -863,7 +863,7 @@ split_point_start: // At split points actual search starts from here
           ext = ONE_PLY;
 
       else if (givesCheck && pos.see_sign(move) >= 0)
-          ext = PvNode ? ONE_PLY : ONE_PLY / 2;
+          ext = ONE_PLY / 2;
 
       // Singular extension search. If all moves but one fail low on a search of
       // (alpha-s, beta-s), and just one fails high on (alpha, beta), then that move
@@ -1052,6 +1052,7 @@ split_point_start: // At split points actual search starts from here
       // Step 19. Check for split
       if (   !SpNode
           &&  depth >= Threads.min_split_depth()
+          &&  depth - reduction<PvNode>(depth, moveCount) >= Threads.min_split_depth()
           &&  bestValue < beta
           &&  Threads.available_slave_exists(thisThread)
           && !Signals.stop