Reset DrawValue[] before new search

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 2ae1c368c4e76b62c17f8e275b27ed32a5f5f1d8..216964ab43d5434678695f1f9c88d076cb084243 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -45,6 +45,7 @@ namespace Search {
   Color RootColor;
   Time::point SearchTime;
   StateStackPtr SetupStates;
+  Value Contempt[2]; // [bestValue > VALUE_DRAW]
 }
 
 using std::string;
@@ -185,9 +186,9 @@ void Search::think() {
   RootColor = RootPos.side_to_move();
   TimeMgr.init(Limits, RootPos.game_ply(), RootColor);
 
-  int cf = Options["Contempt Factor"] * PawnValueEg / 100; // From centipawns
-  DrawValue[ RootColor] = VALUE_DRAW - Value(cf);
-  DrawValue[~RootColor] = VALUE_DRAW + Value(cf);
+  DrawValue[0] = DrawValue[1] = VALUE_DRAW;
+  Contempt[0] =  Options["Contempt Factor"] * PawnValueEg / 100; // From centipawns
+  Contempt[1] = (Options["Contempt Factor"] + 12) * PawnValueEg / 100;
 
   if (RootMoves.empty())
   {
@@ -339,6 +340,9 @@ namespace {
             {
                 bestValue = search<Root>(pos, ss, alpha, beta, depth * ONE_PLY, false);
 
+                DrawValue[ RootColor] = VALUE_DRAW - Contempt[bestValue > VALUE_DRAW];
+                DrawValue[~RootColor] = VALUE_DRAW + Contempt[bestValue > VALUE_DRAW];
+
                 // Bring the best move to the front. It is critical that sorting
                 // is done with a stable algorithm because all the values but the
                 // first and eventually the new best one are set to -VALUE_INFINITE