Update failedHighCnt rule #2063

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 5d6babb45f716200c82dd30b2265d9857a0e81b3..fdef140026bd529a52390e8954f536eff42fa5ef 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -149,7 +149,7 @@ namespace {
 void Search::init() {
 
   for (int i = 1; i < MAX_MOVES; ++i)
-      Reductions[i] = int(1024 * std::log(i) / std::sqrt(1.95));
+     Reductions[i] = int(733.3 * std::log(i));
 }
 
 
@@ -241,10 +241,8 @@ void MainThread::search() {
 
       // Vote according to score and depth
       for (Thread* th : Threads)
-      {
-          int64_t s = th->rootMoves[0].score - minScore + 1;
-          votes[th->rootMoves[0].pv[0]] += 200 + s * s * int(th->completedDepth);
-      }
+          votes[th->rootMoves[0].pv[0]] +=
+               (th->rootMoves[0].score - minScore + 14) * int(th->completedDepth);
 
       // Select best thread
       auto bestVote = votes[this->rootMoves[0].pv[0]];
@@ -406,17 +404,14 @@ void Thread::search() {
                   beta = (alpha + beta) / 2;
                   alpha = std::max(bestValue - delta, -VALUE_INFINITE);
 
+                  failedHighCnt = 0;
                   if (mainThread)
-                  {
-                      failedHighCnt = 0;
                       mainThread->stopOnPonderhit = false;
-                  }
               }
               else if (bestValue >= beta)
               {
                   beta = std::min(bestValue + delta, VALUE_INFINITE);
-                  if (mainThread)
-                      ++failedHighCnt;
+                  ++failedHighCnt;
               }
               else
                   break;
@@ -855,6 +850,7 @@ moves_loop: // When in check, search starts from here
     value = bestValue; // Workaround a bogus 'uninitialized' warning under gcc
     moveCountPruning = false;
     ttCapture = ttMove && pos.capture_or_promotion(ttMove);
+    int singularExtensionLMRmultiplier = 0;
 
     // Step 12. Loop through all pseudo-legal moves until no moves remain
     // or a beta cutoff occurs.
@@ -911,7 +907,12 @@ moves_loop: // When in check, search starts from here
           ss->excludedMove = MOVE_NONE;
 
           if (value < singularBeta)
+              {
               extension = ONE_PLY;
+              singularExtensionLMRmultiplier++;
+              if (value < singularBeta - std::min(3 * depth / ONE_PLY, 39))
+                 singularExtensionLMRmultiplier++;
+              }
 
           // Multi-cut pruning
           // Our ttMove is assumed to fail high, and now we failed high also on a reduced
@@ -1021,6 +1022,8 @@ moves_loop: // When in check, search starts from here
           // Decrease reduction if opponent's move count is high (~10 Elo)
           if ((ss-1)->moveCount > 15)
               r -= ONE_PLY;
+          // Decrease reduction if move has been singularly extended
+          r -= singularExtensionLMRmultiplier * ONE_PLY;
 
           if (!captureOrPromotion)
           {