X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fevaluate.cpp;h=51d9b4290e6d48b3b324de5e6c459d5fd9d824a2;hp=1ee727da59773a5920835db74eb5f6e6bf6ea855;hb=c9dcda6ac488c0058ebd567e1f52e30b8cd0db20;hpb=26689d8c2ae506e4da1a5654fcfdfe04886c3692

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 1ee727da..51d9b429 100644
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2013 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -163,7 +163,6 @@ namespace {
   #undef S
 
   const Score Tempo            = make_score(24, 11);
-  const Score BishopPin        = make_score(66, 11);
   const Score RookOn7th        = make_score(11, 20);
   const Score QueenOn7th       = make_score( 3,  8);
   const Score RookOnPawn       = make_score(10, 28);
@@ -207,19 +206,6 @@ namespace {
   const int BishopCheck       = 2;
   const int KnightCheck       = 3;
 
-  // KingExposed[Square] contains penalties based on the position of the
-  // defending king, indexed by king's square (from white's point of view).
-  const int KingExposed[] = {
-     2,  0,  2,  5,  5,  2,  0,  2,
-     2,  2,  4,  8,  8,  4,  2,  2,
-     7, 10, 12, 12, 12, 12, 10,  7,
-    15, 15, 15, 15, 15, 15, 15, 15,
-    15, 15, 15, 15, 15, 15, 15, 15,
-    15, 15, 15, 15, 15, 15, 15, 15,
-    15, 15, 15, 15, 15, 15, 15, 15,
-    15, 15, 15, 15, 15, 15, 15, 15
-  };
-
   // KingDanger[Color][attackUnits] contains the actual king danger weighted
   // scores, indexed by color and by a calculated integer number.
   Score KingDanger[COLOR_NB][128];
@@ -434,7 +420,7 @@ Value do_evaluate(const Position& pos) {
     {
         ei.kingRing[Them] = b | shift_bb<Down>(b);
         b &= ei.attackedBy[Us][PAWN];
-        ei.kingAttackersCount[Us] = b ? popcount<Max15>(b) / 2 : 0;
+        ei.kingAttackersCount[Us] = b ? popcount<Max15>(b) : 0;
         ei.kingAdjacentZoneAttacksCount[Us] = ei.kingAttackersWeight[Us] = 0;
     }
     else
@@ -514,13 +500,6 @@ Value do_evaluate(const Position& pos) {
         if (ei.attackedBy[Them][PAWN] & s)
             score -= ThreatenedByPawn[Piece];
 
-        // Otherwise give a bonus if we are a bishop and can pin a piece or can
-        // give a discovered check through an x-ray attack.
-        else if (    Piece == BISHOP
-                 && (PseudoAttacks[Piece][pos.king_square(Them)] & s)
-                 && !more_than_one(BetweenBB[s][pos.king_square(Them)] & pos.pieces()))
-                 score += BishopPin;
-
         // Penalty for bishop with same coloured pawns
         if (Piece == BISHOP)
             score -= BishopPawns * ei.pi->pawns_on_same_color_squares(Us, s);
@@ -640,8 +619,7 @@ Value do_evaluate(const Position& pos) {
     Score score = ei.pi->king_safety<Us>(pos, ksq);
 
     // Main king safety evaluation
-    if (   ei.kingAttackersCount[Them] >= 2
-        && ei.kingAdjacentZoneAttacksCount[Them])
+    if (ei.kingAttackersCount[Them])
     {
         // Find the attacked squares around the king which have no defenders
         // apart from the king itself
@@ -654,11 +632,10 @@ Value do_evaluate(const Position& pos) {
         // Initialize the 'attackUnits' variable, which is used later on as an
         // index to the KingDanger[] array. The initial value is based on the
         // number and types of the enemy's attacking pieces, the number of
-        // attacked and undefended squares around our king, the square of the
-        // king, and the quality of the pawn shelter.
+        // attacked and undefended squares around our king and the quality of
+        // the pawn shelter (current 'score' value).
         attackUnits =  std::min(20, (ei.kingAttackersCount[Them] * ei.kingAttackersWeight[Them]) / 2)
                      + 3 * (ei.kingAdjacentZoneAttacksCount[Them] + popcount<Max15>(undefended))
-                     + KingExposed[relative_square(Us, ksq)]
                      - mg_value(score) / 32;
 
         // Analyse the enemy's safe queen contact checks. Firstly, find the