Be more optimistic in aspiration window

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index f6cf7090f1e2dfd681a8d3b2bac3540a62c55228..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;
@@ -1541,7 +1541,7 @@ void Thread::idle_loop() {
 void check_time() {
 
   static Time::point lastInfoTime = Time::now();
-  int64_t nodes = 0; // Workaround silly 'uninitialized' gcc warning
+  Time::point elapsed = Time::now() - SearchTime;
 
   if (Time::now() - lastInfoTime >= 1000)
   {
@@ -1549,14 +1549,24 @@ void check_time() {
       dbg_print();
   }
 
-  if (Limits.ponder)
-      return;
+  if (Limits.use_time_management() && !Limits.ponder)
+  {
+      bool stillAtFirstMove =    Signals.firstRootMove
+                             && !Signals.failedLowAtRoot
+                             &&  elapsed > TimeMgr.available_time() * 75 / 100;
+
+      if (   stillAtFirstMove
+          || elapsed > TimeMgr.maximum_time() - 2 * TimerThread::Resolution)
+          Signals.stop = true;
+  }
+  else if (Limits.movetime && elapsed >= Limits.movetime)
+      Signals.stop = true;
 
-  if (Limits.nodes)
+  else if (Limits.nodes)
   {
       Threads.mutex.lock();
 
-      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.
@@ -1577,18 +1587,8 @@ void check_time() {
           }
 
       Threads.mutex.unlock();
-  }
-
-  Time::point elapsed = Time::now() - SearchTime;
-  bool stillAtFirstMove =    Signals.firstRootMove
-                         && !Signals.failedLowAtRoot
-                         &&  elapsed > TimeMgr.available_time() * 75 / 100;
 
-  bool noMoreTime =   elapsed > TimeMgr.maximum_time() - 2 * TimerThread::Resolution
-                   || stillAtFirstMove;
-
-  if (   (Limits.use_time_management() && noMoreTime)
-      || (Limits.movetime && elapsed >= Limits.movetime)
-      || (Limits.nodes && nodes >= Limits.nodes))
-      Signals.stop = true;
+      if (nodes >= Limits.nodes)
+          Signals.stop = true;
+  }
 }