Simplify pruning

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 8987b0ecd0a72cc7337404f604ecb951b254e889..0136db840f7031e5142919e9b97561d94b57496d 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -194,10 +194,10 @@ namespace {
   const Score OtherCheck          = S(10, 10);
   const Score ThreatByHangingPawn = S(71, 61);
   const Score LooseEnemies        = S( 0, 25);
-  const Score WeakQueen           = S(35,  0);
+  const Score WeakQueen           = S(50, 10);
   const Score Hanging             = S(48, 27);
   const Score ThreatByPawnPush    = S(38, 22);
-  const Score Unstoppable         = S( 0, 20);
+  const Score Unstoppable         = S( 0, 45);
   const Score PawnlessFlank       = S(20, 80);
   const Score HinderPassedPawn    = S( 7,  0);
   const Score ThreatByRank        = S(16,  3);
@@ -349,7 +349,6 @@ namespace {
                 Square ksq = pos.square<KING>(Us);
 
                 if (   ((file_of(ksq) < FILE_E) == (file_of(s) < file_of(ksq)))
-                    && (rank_of(ksq) == rank_of(s) || relative_rank(Us, ksq) == RANK_1)
                     && !ei.pi->semiopen_side(Us, file_of(ksq), file_of(s) < file_of(ksq)))
                     score -= (TrappedRook - make_score(mob * 22, 0)) * (1 + !pos.can_castle(Us));
             }
@@ -856,12 +855,11 @@ Value Eval::evaluate(const Position& pos) {
   // If both sides have only pawns, score for potential unstoppable pawns
   if (!pos.non_pawn_material(WHITE) && !pos.non_pawn_material(BLACK))
   {
-      Bitboard b;
-      if ((b = ei.pi->passed_pawns(WHITE)) != 0)
-          score += Unstoppable * int(relative_rank(WHITE, frontmost_sq(WHITE, b)));
+      if (ei.pi->passed_pawns(WHITE))
+          score += Unstoppable;
 
-      if ((b = ei.pi->passed_pawns(BLACK)) != 0)
-          score -= Unstoppable * int(relative_rank(BLACK, frontmost_sq(BLACK, b)));
+      if (ei.pi->passed_pawns(BLACK))
+          score -= Unstoppable;
   }
 
   // Evaluate space for both sides, only during opening
@@ -888,8 +886,9 @@ Value Eval::evaluate(const Position& pos) {
       Trace::add(IMBALANCE, ei.me->imbalance());
       Trace::add(PAWN, ei.pi->pawns_score());
       Trace::add(MOBILITY, mobility[WHITE], mobility[BLACK]);
-      Trace::add(SPACE, evaluate_space<WHITE>(pos, ei)
-                      , evaluate_space<BLACK>(pos, ei));
+      if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >= 12222)
+          Trace::add(SPACE, evaluate_space<WHITE>(pos, ei)
+                          , evaluate_space<BLACK>(pos, ei));
       Trace::add(TOTAL, score);
   }