Be more optimistic in aspiration window

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 8099787ec71980751e8fa826f641e058326e0609..2b58eda81891fb2c2709e5096fdd1e4889adae91 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -322,18 +322,22 @@ namespace {
                 // re-search, otherwise exit the loop.
                 if (bestValue <= alpha)
                 {
+                    beta = (alpha + beta) / 2;
                     alpha = std::max(bestValue - delta, -VALUE_INFINITE);
 
                     Signals.failedLowAtRoot = true;
                     Signals.stopOnPonderhit = false;
                 }
                 else if (bestValue >= beta)
+                {
+                    alpha = (alpha + beta) / 2;
                     beta = std::min(bestValue + delta, VALUE_INFINITE);
+                }
 
                 else
                     break;
 
-                delta += 3 * delta / 8;
+                delta += delta / 2;
 
                 assert(alpha >= -VALUE_INFINITE && beta <= VALUE_INFINITE);
             }
@@ -747,7 +751,6 @@ moves_loop: // When in check and at SpNode search starts from here
           && !captureOrPromotion
           && !inCheck
           && !dangerous
-       /* &&  move != ttMove Already implicit in the next condition */
           &&  bestValue > VALUE_MATED_IN_MAX_PLY)
       {
           // Move count based pruning
@@ -813,9 +816,8 @@ moves_loop: // When in check and at SpNode search starts from here
       // Step 15. Reduced depth search (LMR). If the move fails high it will be
       // re-searched at full depth.
       if (    depth >= 3 * ONE_PLY
-          && !pvMove
+          &&  moveCount > 1
           && !captureOrPromotion
-          &&  move != ttMove
           &&  move != ss->killers[0]
           &&  move != ss->killers[1])
       {
@@ -1111,7 +1113,6 @@ moves_loop: // When in check and at SpNode search starts from here
       if (   !PvNode
           && !InCheck
           && !givesCheck
-          &&  move != ttMove
           &&  futilityBase > -VALUE_KNOWN_WIN
           && !pos.advanced_pawn_push(move))
       {
@@ -1141,7 +1142,6 @@ moves_loop: // When in check and at SpNode search starts from here
       // Don't search moves with negative SEE values
       if (   !PvNode
           && (!InCheck || evasionPrunable)
-          &&  move != ttMove
           &&  type_of(move) != PROMOTION
           &&  pos.see_sign(move) < VALUE_ZERO)
           continue;
@@ -1566,7 +1566,7 @@ void check_time() {
   {
       Threads.mutex.lock();
 
-      int nodes = RootPos.nodes_searched();
+      int64_t nodes = RootPos.nodes_searched();
 
       // Loop across all split points and sum accumulated SplitPoint nodes plus
       // all the currently active positions nodes.