X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;ds=sidebyside;f=src%2Fsearch.cpp;h=ad5b364d41d780db779c6b2ce88fa7524987acad;hb=84f3bf594d323ac4fcaac0b6681edcdf2f9da70f;hp=993fa853f47ce51d95c167ae3c951f70fce4f27b;hpb=b7ecdaada7e2690dd286c41d3a73463f06fb088f;p=stockfish

diff --git a/src/search.cpp b/src/search.cpp
index 993fa853..ad5b364d 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -280,7 +280,7 @@ void MainThread::search() {
       std::map<Move, int64_t> votes;
       Value minScore = this->rootMoves[0].score;
 
-      // Find out minimum score
+      // Find minimum score
       for (Thread* th: Threads)
           minScore = std::min(minScore, th->rootMoves[0].score);
 
@@ -290,14 +290,15 @@ void MainThread::search() {
           votes[th->rootMoves[0].pv[0]] +=
               (th->rootMoves[0].score - minScore + 14) * int(th->completedDepth);
 
-          if (bestThread->rootMoves[0].score >= VALUE_TB_WIN_IN_MAX_PLY)
+          if (abs(bestThread->rootMoves[0].score) >= VALUE_TB_WIN_IN_MAX_PLY)
           {
-              // Make sure we pick the shortest mate
+              // Make sure we pick the shortest mate / TB conversion or stave off mate the longest
               if (th->rootMoves[0].score > bestThread->rootMoves[0].score)
                   bestThread = th;
           }
           else if (   th->rootMoves[0].score >= VALUE_TB_WIN_IN_MAX_PLY
-                   || votes[th->rootMoves[0].pv[0]] > votes[bestThread->rootMoves[0].pv[0]])
+                   || (   th->rootMoves[0].score > VALUE_TB_LOSS_IN_MAX_PLY
+                       && votes[th->rootMoves[0].pv[0]] > votes[bestThread->rootMoves[0].pv[0]]))
               bestThread = th;
       }
   }
@@ -867,7 +868,7 @@ namespace {
 
         if (nullValue >= beta)
         {
-            // Do not return unproven mate scores
+            // Do not return unproven mate or TB scores
             if (nullValue >= VALUE_TB_WIN_IN_MAX_PLY)
                 nullValue = beta;