X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=e8ca5c5896d3302edf467b5cedfc11519fb169cd;hp=b54ff19648d7adce0fd1b4f04f7c11afada68bbd;hb=20484ccdd5876deee4138d8badea4ef44b73341f;hpb=e0f42aa956e731b5faae0585f5cc47da23fbe53c

diff --git a/src/search.cpp b/src/search.cpp
index b54ff196..e8ca5c58 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -335,6 +335,7 @@ void Thread::search() {
   MainThread* mainThread = (this == Threads.main() ? Threads.main() : nullptr);
   double timeReduction = 1, totBestMoveChanges = 0;
   Color us = rootPos.side_to_move();
+  int iterIdx = 0;
 
   std::memset(ss-7, 0, 10 * sizeof(Stack));
   for (int i = 7; i > 0; i--)
@@ -345,6 +346,16 @@ void Thread::search() {
   bestValue = delta = alpha = -VALUE_INFINITE;
   beta = VALUE_INFINITE;
 
+  if (mainThread)
+  {
+      if (mainThread->previousScore == VALUE_INFINITE)
+          for (int i=0; i<4; ++i)
+              mainThread->iterValue[i] = VALUE_ZERO;
+      else
+          for (int i=0; i<4; ++i)
+              mainThread->iterValue[i] = mainThread->previousScore;
+  }
+
   size_t multiPV = Options["MultiPV"];
 
   // Pick integer skill levels, but non-deterministically round up or down
@@ -520,7 +531,8 @@ void Thread::search() {
           && !Threads.stop
           && !mainThread->stopOnPonderhit)
       {
-          double fallingEval = (354 + 10 * (mainThread->previousScore - bestValue)) / 692.0;
+          double fallingEval = (354 +  6 * (mainThread->previousScore - bestValue)
+                                    +  6 * (mainThread->iterValue[iterIdx]  - bestValue)) / 692.0;
           fallingEval = clamp(fallingEval, 0.5, 1.5);
 
           // If the bestMove is stable over several iterations, reduce time accordingly
@@ -547,6 +559,9 @@ void Thread::search() {
                   Threads.stop = true;
           }
       }
+
+      mainThread->iterValue[iterIdx] = bestValue;
+      iterIdx = (iterIdx + 1) & 3;
   }
 
   if (!mainThread)
@@ -1033,8 +1048,7 @@ moves_loop: // When in check, search starts from here
           // search without the ttMove. So we assume this expected Cut-node is not singular,
           // that multiple moves fail high, and we can prune the whole subtree by returning
           // a soft bound.
-          else if (   eval >= beta
-                   && singularBeta >= beta)
+          else if (singularBeta >= beta)
               return singularBeta;
       }
 
@@ -1049,6 +1063,12 @@ moves_loop: // When in check, search starts from here
                && pos.pawn_passed(us, to_sq(move)))
           extension = 1;
 
+      // Last captures extension
+      else if (   PvNode
+               && PieceValue[EG][pos.captured_piece()] > PawnValueEg
+               && pos.non_pawn_material() <= 2 * RookValueMg)
+          extension = 1;
+
       // Castling extension
       if (type_of(move) == CASTLING)
           extension = 1;
@@ -1084,7 +1104,8 @@ moves_loop: // When in check, search starts from here
           && (  !captureOrPromotion
               || moveCountPruning
               || ss->staticEval + PieceValue[EG][pos.captured_piece()] <= alpha
-              || cutNode))
+              || cutNode
+              || thisThread->ttHitAverage < 384 * ttHitAverageResolution * ttHitAverageWindow / 1024))
       {
           Depth r = reduction(improving, depth, moveCount);