X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=07680f1d1830e4447c7f61da25be41407bc69510;hp=7dc674882ee4315b3fe8922c7ab6d2252ab456c9;hb=b9f1c9bf3f5ba240423a4f1ca8a2fb0f975a775e;hpb=97d2cc9a9c1c4b6ff1b470676fa18c7fc6509886

diff --git a/src/search.cpp b/src/search.cpp
index 7dc67488..07680f1d 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -187,6 +187,7 @@ void Search::clear() {
   Time.availableNodes = 0;
   TT.clear();
   Threads.clear();
+  Tablebases::init(Options["SyzygyPath"]); // Free up mapped files
 }
 
 
@@ -387,7 +388,7 @@ void Thread::search() {
           if (rootDepth >= 5 * ONE_PLY)
           {
               Value previousScore = rootMoves[pvIdx].previousScore;
-              delta = Value(18);
+              delta = Value(20);
               alpha = std::max(previousScore - delta,-VALUE_INFINITE);
               beta  = std::min(previousScore + delta, VALUE_INFINITE);
 
@@ -401,9 +402,11 @@ void Thread::search() {
           // Start with a small aspiration window and, in the case of a fail
           // high/low, re-search with a bigger window until we don't fail
           // high/low anymore.
+          int failedHighCnt = 0;
           while (true)
           {
-              bestValue = ::search<PV>(rootPos, ss, alpha, beta, rootDepth, false);
+              Depth adjustedDepth = std::max(ONE_PLY, rootDepth - failedHighCnt * ONE_PLY);
+              bestValue = ::search<PV>(rootPos, ss, alpha, beta, adjustedDepth, false);
 
               // Bring the best move to the front. It is critical that sorting
               // is done with a stable algorithm because all the values but the
@@ -436,12 +439,17 @@ void Thread::search() {
 
                   if (mainThread)
                   {
+                      failedHighCnt = 0;
                       failedLow = true;
                       Threads.stopOnPonderhit = false;
                   }
               }
               else if (bestValue >= beta)
+              {
                   beta = std::min(bestValue + delta, VALUE_INFINITE);
+                  if (mainThread)
+                	  ++failedHighCnt;
+              }
               else
                   break;
 
@@ -933,10 +941,15 @@ moves_loop: // When in check, search starts from here
               extension = ONE_PLY;
       }
       else if (    givesCheck // Check extension (~2 Elo)
-               && !moveCountPruning
                &&  pos.see_ge(move))
           extension = ONE_PLY;
 
+      // Extension for king moves that change castling rights
+      if (   pos.can_castle(us)
+          && type_of(movedPiece) == KING
+          && depth < 12 * ONE_PLY)
+          extension = ONE_PLY;
+
       // Calculate new depth for this move
       newDepth = depth - ONE_PLY + extension;
 
@@ -1133,8 +1146,6 @@ moves_loop: // When in check, search starts from here
                   break;
               }
           }
-          else if (PvNode && !rootNode && value == alpha)
-              update_pv(ss->pv, move, (ss+1)->pv);
       }
 
       if (move != bestMove)