Tuned nullmove search

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 116d5d6616838696d1b6787a85d8fc2f029e7c40..27fcd47763060dd260812124b2b9bffb7ca4a491 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -145,7 +145,7 @@ namespace {
   constexpr Score ThreatByKing       = S( 24, 89);
   constexpr Score ThreatByPawnPush   = S( 48, 39);
   constexpr Score ThreatBySafePawn   = S(173, 94);
-  constexpr Score TrappedRook        = S( 47,  4);
+  constexpr Score TrappedRook        = S( 52, 10);
   constexpr Score WeakQueen          = S( 49, 15);
 
 #undef S
@@ -225,9 +225,9 @@ namespace {
     // Find our pawns that are blocked or on the first two ranks
     Bitboard b = pos.pieces(Us, PAWN) & (shift<Down>(pos.pieces()) | LowRanks);
 
-    // Squares occupied by those pawns, by our king or queen or controlled by
-    // enemy pawns are excluded from the mobility area.
-    mobilityArea[Us] = ~(b | pos.pieces(Us, KING, QUEEN) | pe->pawn_attacks(Them));
+    // Squares occupied by those pawns, by our king or queen, by blockers to attacks on our king
+    // or controlled by enemy pawns are excluded from the mobility area.
+    mobilityArea[Us] = ~(b | pos.pieces(Us, KING, QUEEN) | pos.blockers_for_king(Us) | pe->pawn_attacks(Them));
 
     // Initialize attackedBy[] for king and pawns
     attackedBy[Us][KING] = pos.attacks_from<KING>(ksq);
@@ -602,8 +602,8 @@ namespace {
             Square blockSq = s + Up;
 
             // Adjust bonus based on the king's proximity
-            bonus += make_score(0, (  king_proximity(Them, blockSq) * 5
-                                    - king_proximity(Us,   blockSq) * 2) * w);
+            bonus += make_score(0, (  (king_proximity(Them, blockSq) * 19) / 4
+                                     - king_proximity(Us,   blockSq) *  2) * w);
 
             // If blockSq is not the queening square then consider also a second push
             if (r != RANK_7)
@@ -705,6 +705,9 @@ namespace {
     int outflanking =  distance<File>(pos.square<KING>(WHITE), pos.square<KING>(BLACK))
                      - distance<Rank>(pos.square<KING>(WHITE), pos.square<KING>(BLACK));
 
+    bool infiltration =   rank_of(pos.square<KING>(WHITE)) > RANK_4
+                       || rank_of(pos.square<KING>(BLACK)) < RANK_5;
+
     bool pawnsOnBothFlanks =   (pos.pieces(PAWN) & QueenSide)
                             && (pos.pieces(PAWN) & KingSide);
 
@@ -716,10 +719,11 @@ namespace {
     int complexity =   9 * pe->passed_count()
                     + 11 * pos.count<PAWN>()
                     +  9 * outflanking
+                    + 12 * infiltration
                     + 21 * pawnsOnBothFlanks
                     + 51 * !pos.non_pawn_material()
                     - 43 * almostUnwinnable
-                    - 95 ;
+                    - 100 ;
 
     // Now apply the bonus: note that we find the attacking side by extracting the
     // sign of the midgame or endgame values, and that we carefully cap the bonus
@@ -847,6 +851,9 @@ Value Eval::evaluate(const Position& pos) {
 
 std::string Eval::trace(const Position& pos) {
 
+  if (pos.checkers())
+      return "Total evaluation: none (in check)";
+
   std::memset(scores, 0, sizeof(scores));
 
   pos.this_thread()->contempt = SCORE_ZERO; // Reset any dynamic contempt