Extend all moves at low depth if ttMove is doubly extended

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 04f73e1c0a28da06dd764352656a6725386524d3..ec7cff5413e8ae2935f3b3a2775b0e5e3114fb5d 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -1067,7 +1067,10 @@ moves_loop: // When in check, search starts here
                   if (  !PvNode
                       && value < singularBeta - 25
                       && ss->doubleExtensions <= 9)
+                  {
                       extension = 2;
+                      depth += depth < 12;
+                  }
               }
 
               // Multi-cut pruning
@@ -1296,7 +1299,7 @@ moves_loop: // When in check, search starts here
                       && depth < 6
                       && beta  <  VALUE_KNOWN_WIN
                       && alpha > -VALUE_KNOWN_WIN)
-                     depth -= 1;
+                      depth -= 1;
 
                   assert(depth > 0);
               }
@@ -1521,7 +1524,6 @@ moves_loop: // When in check, search starts here
           &&  futilityBase > -VALUE_KNOWN_WIN
           &&  type_of(move) != PROMOTION)
       {
-
           if (moveCount > 2)
               continue;