Remove ThreatByHangingPawn bonus (#1356)

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index c6740b5f65ba0f45f67c177f5b0ca1da13540589..fa3b0a720b2face4a2ac66d6085370f3b8e77e43 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -2,7 +2,7 @@
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
   Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad

-  Copyright (C) 2015-2017 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+  Copyright (C) 2015-2018 Marco Costalba, Joona Kiiski, Gary Linscott, 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
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by


@@ -220,7 +220,6 @@ namespace {
   const Score WeakQueen             = S( 50, 10);
   const Score CloseEnemies          = S(  7,  0);
   const Score PawnlessFlank         = S( 20, 80);
   const Score WeakQueen             = S( 50, 10);
   const Score CloseEnemies          = S(  7,  0);
   const Score PawnlessFlank         = S( 20, 80);

-  const Score ThreatByHangingPawn   = S( 71, 61);

   const Score ThreatBySafePawn      = S(192,175);
   const Score ThreatByRank          = S( 16,  3);
   const Score Hanging               = S( 48, 27);
   const Score ThreatBySafePawn      = S(192,175);
   const Score ThreatByRank          = S( 16,  3);
   const Score Hanging               = S( 48, 27);


@@ -543,9 +542,6 @@ namespace {
         safeThreats = (shift<Right>(b) | shift<Left>(b)) & weak;
 
         score += ThreatBySafePawn * popcount(safeThreats);
         safeThreats = (shift<Right>(b) | shift<Left>(b)) & weak;
 
         score += ThreatBySafePawn * popcount(safeThreats);

-
-        if (weak ^ safeThreats)
-            score += ThreatByHangingPawn;

     }
 
     // Squares strongly protected by the opponent, either because they attack the
     }
 
     // Squares strongly protected by the opponent, either because they attack the