Retire loose enemies bonus

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 9e0629ef66686f816cc81041f801ebc3feb52829..6cd33bd503de049c65da7984259f754fce94721f 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -190,7 +190,6 @@ namespace {
   const Score OtherCheck          = S(10, 10);
   const Score CloseEnemies        = S( 7,  0);
   const Score PawnlessFlank       = S(20, 80);
-  const Score LooseEnemies        = S( 0, 25);
   const Score ThreatByHangingPawn = S(71, 61);
   const Score ThreatByRank        = S(16,  3);
   const Score Hanging             = S(48, 27);
@@ -515,11 +514,6 @@ namespace {
     Bitboard b, weak, defended, safeThreats;
     Score score = SCORE_ZERO;
 
-    // Small bonus if the opponent has loose pawns or pieces
-    if (   (pos.pieces(Them) ^ pos.pieces(Them, QUEEN, KING))
-        & ~(ei.attackedBy[Us][ALL_PIECES] | ei.attackedBy[Them][ALL_PIECES]))
-        score += LooseEnemies;
-
     // Non-pawn enemies attacked by a pawn
     weak = (pos.pieces(Them) ^ pos.pieces(Them, PAWN)) & ei.attackedBy[Us][PAWN];
 
@@ -667,10 +661,6 @@ namespace {
                 mbonus += rr + r * 2, ebonus += rr + r * 2;
         } // rr != 0
 
-        // Assign a small bonus when the opponent has no pieces left
-        if (!pos.non_pawn_material(Them))
-            ebonus += 20;
-
         // Scale down bonus for candidate passers which need more than one pawn
         // push to become passed.
         if (!pos.pawn_passed(Us, s + pawn_push(Us)))
@@ -755,8 +745,7 @@ namespace {
 
     // If we don't already have an unusual scale factor, check for certain
     // types of endgames, and use a lower scale for those.
-    if (    ei.me->game_phase() < PHASE_MIDGAME
-        && (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN))
+    if (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN)
     {
         if (pos.opposite_bishops())
         {
@@ -764,19 +753,18 @@ namespace {
             // is almost a draw, in case of KBP vs KB, it is even more a draw.
             if (   pos.non_pawn_material(WHITE) == BishopValueMg
                 && pos.non_pawn_material(BLACK) == BishopValueMg)
-                sf = more_than_one(pos.pieces(PAWN)) ? ScaleFactor(31) : ScaleFactor(9);
+                return more_than_one(pos.pieces(PAWN)) ? ScaleFactor(31) : ScaleFactor(9);
 
             // Endgame with opposite-colored bishops, but also other pieces. Still
             // a bit drawish, but not as drawish as with only the two bishops.
-            else
-                sf = ScaleFactor(46);
+            return ScaleFactor(46);
         }
         // Endings where weaker side can place his king in front of the opponent's
         // pawns are drawish.
         else if (    abs(eg) <= BishopValueEg
                  &&  pos.count<PAWN>(strongSide) <= 2
                  && !pos.pawn_passed(~strongSide, pos.square<KING>(~strongSide)))
-            sf = ScaleFactor(37 + 7 * pos.count<PAWN>(strongSide));
+            return ScaleFactor(37 + 7 * pos.count<PAWN>(strongSide));
     }
 
     return sf;