Revert dynamic contempt
authorMarco Costalba <mcostalba@gmail.com>
Sun, 4 May 2014 07:58:49 +0000 (09:58 +0200)
committerMarco Costalba <mcostalba@gmail.com>
Sun, 4 May 2014 07:58:49 +0000 (09:58 +0200)
On a final fixed game number test it failed
to prove better than standard version.

STC 15+0.05

ELO: -0.86 +-1.7 (95%) LOS: 15.8%
Total: 57578 W: 10070 L: 10213 D: 37295

bench: 8802105

src/search.cpp

index dbc9f0c6d9610499fdc2c389d1b467647bd1039c..cd815c2af266e679294ff81ba0f5806f7b548d4a 100644 (file)
@@ -45,7 +45,6 @@ namespace Search {
   Color RootColor;
   Time::point SearchTime;
   StateStackPtr SetupStates;
-  Value Contempt[2]; // [bestValue > VALUE_DRAW]
 }
 
 using std::string;
@@ -186,9 +185,9 @@ void Search::think() {
   RootColor = RootPos.side_to_move();
   TimeMgr.init(Limits, RootPos.game_ply(), RootColor);
 
-  DrawValue[0] = DrawValue[1] = VALUE_DRAW;
-  Contempt[0] =  Options["Contempt Factor"] * PawnValueEg / 100; // From centipawns
-  Contempt[1] = (Options["Contempt Factor"] + 12) * PawnValueEg / 100;
+  int cf = Options["Contempt Factor"] * PawnValueEg / 100; // From centipawns
+  DrawValue[ RootColor] = VALUE_DRAW - Value(cf);
+  DrawValue[~RootColor] = VALUE_DRAW + Value(cf);
 
   if (RootMoves.empty())
   {
@@ -340,9 +339,6 @@ 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