Fix dynamic contempt for MultiPV

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 1a516ff80b1e7a1c7a95d9d1ac9c9cfd8412e167..7b7737ea9fd2a946303a66b0af53d8235a30a766 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -343,14 +343,15 @@ void Thread::search() {
           // Reset aspiration window starting size
           if (rootDepth >= 5 * ONE_PLY)
           {
+              Value previousScore = rootMoves[PVIdx].previousScore;
               delta = Value(18);
-              alpha = std::max(rootMoves[PVIdx].previousScore - delta,-VALUE_INFINITE);
-              beta  = std::min(rootMoves[PVIdx].previousScore + delta, VALUE_INFINITE);
+              alpha = std::max(previousScore - delta,-VALUE_INFINITE);
+              beta  = std::min(previousScore + delta, VALUE_INFINITE);
 
               ct =  Options["Contempt"] * PawnValueEg / 100; // From centipawns
 
-              // Adjust contempt based on current bestValue (dynamic contempt)
-              ct += int(std::round(48 * atan(float(bestValue) / 128)));
+              // Adjust contempt based on root move's previousScore (dynamic contempt)
+              ct += int(std::round(48 * atan(float(previousScore) / 128)));
 
               Eval::Contempt = (us == WHITE ?  make_score(ct, ct / 2)
                                             : -make_score(ct, ct / 2));