From ef43e6b05d0c79bf2ec7be291866449eba2ef576 Mon Sep 17 00:00:00 2001 From: Leonid Pechenik Date: Thu, 17 Apr 2014 12:49:57 -0400 Subject: [PATCH] Rise contempt when in advantage This is a very discussed patch with many argumentations pro and against. The fact is it passed both STC: LLR: 2.96 (-2.94,2.94) [-1.50,4.50] Total: 16305 W: 3001 L: 2855 D: 10449 And LTC LLR: 2.95 (-2.94,2.94) [0.00,6.00] Total: 34273 W: 5180 L: 4931 D: 24162 Although it is true that a correct test should include foreign engines, we commit it anyhow so people can test it out in the wild, under broader conditions. bench: 7384368 --- src/search.cpp | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/src/search.cpp b/src/search.cpp index 2ae1c368..03af5d66 100644 --- 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 +186,8 @@ 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); + Contempt[0] = Options["Contempt Factor"] * PawnValueEg / 100; // From centipawns + Contempt[1] = (Options["Contempt Factor"] + 12) * PawnValueEg / 100; if (RootMoves.empty()) { @@ -339,6 +339,9 @@ namespace { { bestValue = search(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 -- 2.39.2