Further simplify unstoppable (#938)

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 8987b0ecd0a72cc7337404f604ecb951b254e889..19bfc9fe299820f3c4a95beeb2845f77892a2e47 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -194,10 +194,9 @@ namespace {
   const Score OtherCheck          = S(10, 10);
   const Score ThreatByHangingPawn = S(71, 61);
   const Score LooseEnemies        = S( 0, 25);
   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 Hanging             = S(48, 27);
   const Score ThreatByPawnPush    = S(38, 22);

-  const Score Unstoppable         = S( 0, 20);

   const Score PawnlessFlank       = S(20, 80);
   const Score HinderPassedPawn    = S( 7,  0);
   const Score ThreatByRank        = S(16,  3);
   const Score PawnlessFlank       = S(20, 80);
   const Score HinderPassedPawn    = S( 7,  0);
   const Score ThreatByRank        = S(16,  3);


@@ -349,7 +348,6 @@ namespace {
                 Square ksq = pos.square<KING>(Us);
 
                 if (   ((file_of(ksq) < FILE_E) == (file_of(s) < file_of(ksq)))
                 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));
             }
                     && !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));
             }


@@ -679,6 +677,10 @@ namespace {
                 mbonus += rr + r * 2, ebonus += rr + r * 2;
         } // rr != 0
 
                 mbonus += rr + r * 2, ebonus += rr + r * 2;
         } // rr != 0
 

+        // Assign a small bonus when no pieces left (unstoppable)
+        if (!pos.non_pawn_material(Us) && !pos.non_pawn_material(Them))
+            ebonus += 20;
+

         score += make_score(mbonus, ebonus) + PassedFile[file_of(s)];
     }
 
         score += make_score(mbonus, ebonus) + PassedFile[file_of(s)];
     }
 


@@ -853,17 +855,6 @@ Value Eval::evaluate(const Position& pos) {
   score +=  evaluate_passed_pawns<WHITE, DoTrace>(pos, ei)
           - evaluate_passed_pawns<BLACK, DoTrace>(pos, ei);
 
   score +=  evaluate_passed_pawns<WHITE, DoTrace>(pos, ei)
           - evaluate_passed_pawns<BLACK, DoTrace>(pos, ei);
 

-  // 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 ((b = ei.pi->passed_pawns(BLACK)) != 0)
-          score -= Unstoppable * int(relative_rank(BLACK, frontmost_sq(BLACK, b)));
-  }
-

   // Evaluate space for both sides, only during opening
   if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >= 12222)
       score +=  evaluate_space<WHITE>(pos, ei)
   // Evaluate space for both sides, only during opening
   if (pos.non_pawn_material(WHITE) + pos.non_pawn_material(BLACK) >= 12222)
       score +=  evaluate_space<WHITE>(pos, ei)


@@ -888,8 +879,9 @@ 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(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);
   }
 
       Trace::add(TOTAL, score);
   }