Improve Stats definition

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 0619db3a12a2420a2ef85864ab84e709c614a158..e36c69593e307d17aa18bf0fe9d2d60fc1b39305 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -82,7 +82,7 @@ namespace {
   // History and stats update bonus, based on depth
   int stat_bonus(Depth depth) {
     int d = depth / ONE_PLY;
-    return d > 17 ? 0 : 32 * d * d + 64 * d - 64;
+    return d > 17 ? 0 : 33 * d * d + 66 * d - 66;
   }
 
   // Skill structure is used to implement strength limit
@@ -290,7 +290,7 @@ void Thread::search() {
 
   std::memset(ss-4, 0, 7 * sizeof(Stack));
   for (int i = 4; i > 0; i--)
-     (ss-i)->continuationHistory = this->continuationHistory[NO_PIECE][0].get(); // Use as sentinel
+     (ss-i)->continuationHistory = &this->continuationHistory[NO_PIECE][0]; // Use as sentinel
 
   bestValue = delta = alpha = -VALUE_INFINITE;
   beta = VALUE_INFINITE;
@@ -587,7 +587,7 @@ namespace {
 
     (ss+1)->ply = ss->ply + 1;
     ss->currentMove = (ss+1)->excludedMove = bestMove = MOVE_NONE;
-    ss->continuationHistory = thisThread->continuationHistory[NO_PIECE][0].get();
+    ss->continuationHistory = &thisThread->continuationHistory[NO_PIECE][0];
     (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE;
     Square prevSq = to_sq((ss-1)->currentMove);
 
@@ -751,7 +751,7 @@ namespace {
         Depth R = ((823 + 67 * depth / ONE_PLY) / 256 + std::min((eval - beta) / PawnValueMg, 3)) * ONE_PLY;
 
         ss->currentMove = MOVE_NULL;
-        ss->continuationHistory = thisThread->continuationHistory[NO_PIECE][0].get();
+        ss->continuationHistory = &thisThread->continuationHistory[NO_PIECE][0];
 
         pos.do_null_move(st);
 
@@ -802,7 +802,7 @@ namespace {
                 probCutCount++;
 
                 ss->currentMove = move;
-                ss->continuationHistory = thisThread->continuationHistory[pos.moved_piece(move)][to_sq(move)].get();
+                ss->continuationHistory = &thisThread->continuationHistory[pos.moved_piece(move)][to_sq(move)];
 
                 assert(depth >= 5 * ONE_PLY);
 
@@ -935,7 +935,7 @@ moves_loop: // When in check, search starts from here
               int lmrDepth = std::max(newDepth - reduction<PvNode>(improving, depth, moveCount), DEPTH_ZERO) / ONE_PLY;
 
               // Countermoves based pruning (~20 Elo)
-              if (   lmrDepth < 3
+              if (   lmrDepth < 3 + ((ss-1)->statScore > 0)
                   && (*contHist[0])[movedPiece][to_sq(move)] < CounterMovePruneThreshold
                   && (*contHist[1])[movedPiece][to_sq(move)] < CounterMovePruneThreshold)
                   continue;
@@ -970,7 +970,7 @@ moves_loop: // When in check, search starts from here
 
       // Update the current move (this must be done after singular extension search)
       ss->currentMove = move;
-      ss->continuationHistory = thisThread->continuationHistory[movedPiece][to_sq(move)].get();
+      ss->continuationHistory = &thisThread->continuationHistory[movedPiece][to_sq(move)];
 
       // Step 15. Make the move
       pos.do_move(move, st, givesCheck);
@@ -985,11 +985,9 @@ moves_loop: // When in check, search starts from here
 
           if (captureOrPromotion) // (~5 Elo)
           {
-              // Increase reduction by comparing opponent's stat score
-              if ((ss-1)->statScore >= 0)
-                  r += ONE_PLY;
-
-              r -= r ? ONE_PLY : DEPTH_ZERO;
+              // Decrease reduction by comparing opponent's stat score
+              if ((ss-1)->statScore < 0)
+                  r -= ONE_PLY;
           }
           else
           {
@@ -1030,10 +1028,10 @@ moves_loop: // When in check, search starts from here
                   r += ONE_PLY;
 
               // Decrease/increase reduction for moves with a good/bad history (~30 Elo)
-              r = std::max(DEPTH_ZERO, (r / ONE_PLY - ss->statScore / 20000) * ONE_PLY);
+              r -= ss->statScore / 20000 * ONE_PLY;
           }
 
-          Depth d = std::max(newDepth - r, ONE_PLY);
+          Depth d = std::max(newDepth - std::max(r, DEPTH_ZERO), ONE_PLY);
 
           value = -search<NonPV>(pos, ss+1, -(alpha+1), -alpha, d, true);
 
@@ -1215,7 +1213,7 @@ moves_loop: // When in check, search starts from here
     Thread* thisThread = pos.this_thread();
     (ss+1)->ply = ss->ply + 1;
     ss->currentMove = bestMove = MOVE_NONE;
-    ss->continuationHistory = thisThread->continuationHistory[NO_PIECE][0].get();
+    ss->continuationHistory = &thisThread->continuationHistory[NO_PIECE][0];
     inCheck = pos.checkers();
     moveCount = 0;
 
@@ -1350,7 +1348,7 @@ moves_loop: // When in check, search starts from here
       }
 
       ss->currentMove = move;
-      ss->continuationHistory = thisThread->continuationHistory[pos.moved_piece(move)][to_sq(move)].get();
+      ss->continuationHistory = &thisThread->continuationHistory[pos.moved_piece(move)][to_sq(move)];
 
       // Make and search the move
       pos.do_move(move, st, givesCheck);