X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fpawns.cpp;h=0642c6799041632263aad067557b2f010df019e6;hp=5662d13ad26b8fbe0a196a55fa5149f4f8bc32b3;hb=8de29390f2d2bd31585b93ff46eae3051126f666;hpb=9742fb10fd83e82ad760e4cac5cef3d6dff670ed

diff --git a/src/pawns.cpp b/src/pawns.cpp
index 5662d13a..0642c679 100644
--- a/src/pawns.cpp
+++ b/src/pawns.cpp
@@ -1,7 +1,8 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2016 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2015-2016 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
@@ -33,32 +34,30 @@ namespace {
 
   // Isolated pawn penalty by opposed flag and file
   const Score Isolated[2][FILE_NB] = {
-    { S(37, 45), S(54, 52), S(60, 52), S(60, 52),
-      S(60, 52), S(60, 52), S(54, 52), S(37, 45) },
-    { S(25, 30), S(36, 35), S(40, 35), S(40, 35),
-      S(40, 35), S(40, 35), S(36, 35), S(25, 30) } };
+    { S(31, 36), S(45, 41), S(50, 41), S(50, 41),
+      S(50, 41), S(50, 41), S(45, 41), S(31, 36) },
+    { S(21, 24), S(30, 28), S(33, 28), S(33, 28),
+      S(33, 28), S(33, 28), S(30, 28), S(21, 24) } };
 
   // Backward pawn penalty by opposed flag
-  const Score Backward[2] = { S(67, 42), S(49, 24) };
-  
-  // Unsupported pawn penalty, for pawns which are neither isolated or backward
-  const Score Unsupported = S(20, 10);
+  const Score Backward[2] = { S(56, 33), S(41, 19) };
+
+  // Unsupported pawn penalty for pawns which are neither isolated or backward,
+  // by number of pawns it supports [less than 2 / exactly 2].
+  const Score Unsupported[2] = { S(17, 8), S(21, 12) };
 
   // Connected pawn bonus by opposed, phalanx, twice supported and rank
   Score Connected[2][2][2][RANK_NB];
-  
+
   // Doubled pawn penalty by file
   const Score Doubled[FILE_NB] = {
-    S(13, 43), S(20, 48), S(23, 48), S(23, 48),
-    S(23, 48), S(23, 48), S(20, 48), S(13, 43) };
+    S(11, 34), S(17, 38), S(19, 38), S(19, 38),
+    S(19, 38), S(19, 38), S(17, 38), S(11, 34) };
 
   // Lever bonus by rank
   const Score Lever[RANK_NB] = {
     S( 0,  0), S( 0,  0), S(0, 0), S(0, 0),
-    S(20, 20), S(40, 40), S(0, 0), S(0, 0) };
-
-  // Center bind bonus, when two pawns controls the same central square
-  const Score CenterBind = S(16, 0);
+    S(17, 16), S(33, 32), S(0, 0), S(0, 0) };
 
   // Weakness of our pawn shelter in front of the king by [distance from edge][rank]
   const Value ShelterWeakness[][RANK_NB] = {
@@ -101,10 +100,6 @@ namespace {
     const Square Right = (Us == WHITE ? DELTA_NE : DELTA_SW);
     const Square Left  = (Us == WHITE ? DELTA_NW : DELTA_SE);
 
-    const Bitboard CenterBindMask =
-      Us == WHITE ? (FileDBB | FileEBB) & (Rank5BB | Rank6BB | Rank7BB)
-                  : (FileDBB | FileEBB) & (Rank4BB | Rank3BB | Rank2BB);
-
     Bitboard b, neighbours, doubled, supported, phalanx;
     Square s;
     bool passed, isolated, opposed, backward, lever, connected;
@@ -181,7 +176,7 @@ namespace {
             score -= Backward[opposed];
 
         else if (!supported)
-            score -= Unsupported;
+            score -= Unsupported[more_than_one(neighbours & rank_bb(s + Up))];
 
         if (connected)
             score += Connected[opposed][!!phalanx][more_than_one(supported)][relative_rank(Us, s)];
@@ -196,9 +191,6 @@ namespace {
     b = e->semiopenFiles[Us] ^ 0xFF;
     e->pawnSpan[Us] = b ? int(msb(b) - lsb(b)) : 0;
 
-    b = shift_bb<Right>(ourPawns) & shift_bb<Left>(ourPawns) & CenterBindMask;
-    score += CenterBind * popcount<Max15>(b);
-
     return score;
   }
 
@@ -212,7 +204,7 @@ namespace Pawns {
 
 void init()
 {
-  static const int Seed[RANK_NB] = { 0, 6, 15, 10, 57, 75, 135, 258 };
+  static const int Seed[RANK_NB] = { 0, 8, 19, 13, 71, 94, 169, 324 };
 
   for (int opposed = 0; opposed <= 1; ++opposed)
       for (int phalanx = 0; phalanx <= 1; ++phalanx)
@@ -221,7 +213,7 @@ void init()
   {
       int v = (Seed[r] + (phalanx ? (Seed[r + 1] - Seed[r]) / 2 : 0)) >> opposed;
       v += (apex ? v / 2 : 0);
-      Connected[opposed][phalanx][apex][r] = make_score(3 * v / 2, v);
+      Connected[opposed][phalanx][apex][r] = make_score(v, v * 5 / 8);
   }
 }