X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=d090f4042177a04cc9975552959930a75f183d9a;hp=515405ca5fe935b16d0eef5fedd103910e9b4968;hb=d66b765eb6b3725b468a3c5f8f2cdb9693fd6bdf;hpb=b1f57e92cea7bd36126ef8c26928d8991b74baef

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 515405ca..d090f404 100644
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -150,6 +150,9 @@ namespace {
 
   #undef S
 
+  // Bonus for having the side to move (modified by Joona Kiiski)
+  const Score Tempo = make_score(24, 11);
+
   // Rooks and queens on the 7th rank (modified by Joona Kiiski)
   const Score RookOn7thBonus  = make_score(47, 98);
   const Score QueenOn7thBonus = make_score(27, 54);
@@ -167,8 +170,8 @@ namespace {
   // happen in Chess960 games.
   const Score TrappedBishopA1H1Penalty = make_score(100, 100);
 
-  // Penalty for BNR that is not defended by anything
-  const Score UndefendedPiecePenalty = make_score(25, 10);
+  // Penalty for an undefended bishop or knight
+  const Score UndefendedMinorPenalty = make_score(25, 10);
 
   // The SpaceMask[Color] contains the area of the board which is considered
   // by the space evaluation. In the middle game, each side is given a bonus
@@ -362,16 +365,17 @@ Value do_evaluate(const Position& pos, Value& margin) {
   Value margins[2];
   Score score, mobilityWhite, mobilityBlack;
 
-  // Initialize score by reading the incrementally updated scores included
-  // in the position object (material + piece square tables).
-  score = pos.psq_score();
-
   // margins[] store the uncertainty estimation of position's evaluation
   // that typically is used by the search for pruning decisions.
   margins[WHITE] = margins[BLACK] = VALUE_ZERO;
 
+  // Initialize score by reading the incrementally updated scores included
+  // in the position object (material + piece square tables) and adding
+  // Tempo bonus. Score is computed from the point of view of white.
+  score = pos.psq_score() + (pos.side_to_move() == WHITE ? Tempo : -Tempo);
+
   // Probe the material hash table
-  ei.mi = this_thread->materialTable.probe(pos);
+  ei.mi = pos.this_thread()->materialTable.probe(pos);
   score += ei.mi->material_value();
 
   // If we have a specialized evaluation function for the current material
@@ -383,7 +387,7 @@ Value do_evaluate(const Position& pos, Value& margin) {
   }
 
   // Probe the pawn hash table
-  ei.pi = this_thread->pawnTable.probe(pos);
+  ei.pi = pos.this_thread()->pawnTable.probe(pos);
   score += ei.pi->pawns_value();
 
   // Initialize attack and king safety bitboards
@@ -676,18 +680,17 @@ Value do_evaluate(const Position& pos, Value& margin) {
 
     const Color Them = (Us == WHITE ? BLACK : WHITE);
 
-    Bitboard b, undefended, undefendedMinors, weakEnemies;
+    Bitboard b, undefendedMinors, weakEnemies;
     Score score = SCORE_ZERO;
 
-    // Undefended pieces get penalized even if not under attack
-    undefended = pos.pieces(Them) & ~ei.attackedBy[Them][0];
-    undefendedMinors = undefended & (pos.pieces(BISHOP) | pos.pieces(KNIGHT));
+    // Undefended minors get penalized even if not under attack
+    undefendedMinors =  pos.pieces(Them)
+                      & (pos.pieces(BISHOP) | pos.pieces(KNIGHT))
+                      & ~ei.attackedBy[Them][0];
 
     if (undefendedMinors)
-        score += single_bit(undefendedMinors) ? UndefendedPiecePenalty
-                                              : UndefendedPiecePenalty * 2;
-    if (undefended & pos.pieces(ROOK))
-        score += UndefendedPiecePenalty;
+        score += single_bit(undefendedMinors) ? UndefendedMinorPenalty
+                                              : UndefendedMinorPenalty * 2;
 
     // Enemy pieces not defended by a pawn and under our attack
     weakEnemies =  pos.pieces(Them)