Increase null verification threshold to 12 plies

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 60667c8764e32a01f904477e66ad614b57b73b57..1abe022aacefa580d699131310127c8a7910437f 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -679,7 +679,7 @@ namespace {
             if (nullValue >= VALUE_MATE_IN_MAX_PLY)
                 nullValue = beta;
 
-            if (depth < 6 * ONE_PLY)
+            if (depth < 12 * ONE_PLY)
                 return nullValue;
 
             // Do verification search at high depths
@@ -1228,7 +1228,7 @@ split_point_start: // At split points actual search starts from here
           // Prune moves with negative or equal SEE
           if (   futilityBase < beta
               && depth < DEPTH_ZERO
-              && pos.see(move) <= 0)
+              && pos.see_asymm(move, beta - futilityBase) <= 0)
           {
               bestValue = std::max(bestValue, futilityBase);
               continue;