Tweak futility pruning depth.

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 2f83f4f45b017fa7a9bfde67c155c28dbcc431a4..886ed52ca0bbf65f3fca476d4bffe12a650f44d2 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -816,7 +816,7 @@ namespace {
 
     // Step 8. Futility pruning: child node (~50 Elo)
     if (   !PvNode
-        &&  depth < 6
+        &&  depth < 8
         &&  eval - futility_margin(depth, improving) >= beta
         &&  eval < VALUE_KNOWN_WIN) // Do not return unproven wins
         return eval;