X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fsearch.cpp;h=8e6efb7a1bd9bdc50e041194f9a8c97b35fade5f;hp=a54d41b9c8fbb34353e3451edfe8739104edf0d9;hb=8ee3124487bdfd871f587bdb46f007ff24fc8303;hpb=9e3ab9099f056a864c2ac7596bf3474dce8ee167

diff --git a/src/search.cpp b/src/search.cpp
index a54d41b9..8e6efb7a 100644
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -107,7 +107,7 @@ namespace {
   const bool UseIIDAtNonPVNodes = false;
 
   // Use null move driven internal iterative deepening?
-  bool UseNullDrivenIID = true;
+  bool UseNullDrivenIID = false;
 
   // Internal iterative deepening margin.  At Non-PV moves, when
   // UseIIDAtNonPVNodes is true, we do an internal iterative deepening search
@@ -2158,31 +2158,34 @@ namespace {
     tto = move_to(threat);
 
     // Case 1: Castling moves are never pruned.
-    if(move_is_castle(m))
-      return false;
+    if (move_is_castle(m))
+        return false;
 
     // Case 2: Don't prune moves which move the threatened piece
-    if(!PruneEscapeMoves && threat != MOVE_NONE && mfrom == tto)
-      return false;
+    if (!PruneEscapeMoves && threat != MOVE_NONE && mfrom == tto)
+        return false;
 
     // Case 3: If the threatened piece has value less than or equal to the
     // value of the threatening piece, don't prune move which defend it.
-    if(!PruneDefendingMoves && threat != MOVE_NONE
-       && (piece_value_midgame(pos.piece_on(tfrom))
-           >= piece_value_midgame(pos.piece_on(tto)))
-       && pos.move_attacks_square(m, tto))
+    if (   !PruneDefendingMoves
+        && threat != MOVE_NONE
+        && pos.type_of_piece_on(tto) != NO_PIECE_TYPE
+        && (   pos.midgame_value_of_piece_on(tfrom) >= pos.midgame_value_of_piece_on(tto)
+            || pos.type_of_piece_on(tfrom) == KING)
+        && pos.move_attacks_square(m, tto))
       return false;
 
     // Case 4: Don't prune moves with good history.
-    if(!H.ok_to_prune(pos.piece_on(move_from(m)), m, d))
-      return false;
+    if (!H.ok_to_prune(pos.piece_on(move_from(m)), m, d))
+        return false;
 
     // Case 5: If the moving piece in the threatened move is a slider, don't
     // prune safe moves which block its ray.
-    if(!PruneBlockingMoves && threat != MOVE_NONE
-       && piece_is_slider(pos.piece_on(tfrom))
-       && bit_is_set(squares_between(tfrom, tto), mto) && pos.see(m) >= 0)
-      return false;
+    if (  !PruneBlockingMoves
+        && threat != MOVE_NONE
+        && piece_is_slider(pos.piece_on(tfrom))
+        && bit_is_set(squares_between(tfrom, tto), mto) && pos.see(m) >= 0)
+            return false;
 
     return true;
   }