Improve move order near the root

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 27fcd47763060dd260812124b2b9bffb7ca4a491..ceba25881058d8135a0f50cdff3afc44d56ea4de 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
-  Copyright (C) 2015-2019 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
+  Copyright (C) 2015-2020 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
@@ -317,20 +317,19 @@ namespace {
                 // Bonus for bishop on a long diagonal which can "see" both center squares
                 if (more_than_one(attacks_bb<BISHOP>(s, pos.pieces(PAWN)) & Center))
                     score += LongDiagonalBishop;
-            }
 
-            // An important Chess960 pattern: A cornered bishop blocked by a friendly
-            // pawn diagonally in front of it is a very serious problem, especially
-            // when that pawn is also blocked.
-            if (   Pt == BISHOP
-                && pos.is_chess960()
-                && (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1)))
-            {
-                Direction d = pawn_push(Us) + (file_of(s) == FILE_A ? EAST : WEST);
-                if (pos.piece_on(s + d) == make_piece(Us, PAWN))
-                    score -= !pos.empty(s + d + pawn_push(Us))                ? CorneredBishop * 4
-                            : pos.piece_on(s + d + d) == make_piece(Us, PAWN) ? CorneredBishop * 2
-                                                                              : CorneredBishop;
+                // An important Chess960 pattern: a cornered bishop blocked by a friendly
+                // pawn diagonally in front of it is a very serious problem, especially
+                // when that pawn is also blocked.
+                if (   pos.is_chess960()
+                    && (s == relative_square(Us, SQ_A1) || s == relative_square(Us, SQ_H1)))
+                {
+                    Direction d = pawn_push(Us) + (file_of(s) == FILE_A ? EAST : WEST);
+                    if (pos.piece_on(s + d) == make_piece(Us, PAWN))
+                        score -= !pos.empty(s + d + pawn_push(Us))                ? CorneredBishop * 4
+                                : pos.piece_on(s + d + d) == make_piece(Us, PAWN) ? CorneredBishop * 2
+                                                                                  : CorneredBishop;
+                }
             }
         }
 
@@ -524,7 +523,6 @@ namespace {
     b =   attackedBy[Them][ALL_PIECES]
        & ~stronglyProtected
        &  attackedBy[Us][ALL_PIECES];
-
     score += RestrictedPiece * popcount(b);
 
     // Protected or unattacked squares
@@ -699,15 +697,9 @@ namespace {
   template<Tracing T>
   Score Evaluation<T>::initiative(Score score) const {
 
-    Value mg = mg_value(score);
-    Value eg = eg_value(score);
-
     int outflanking =  distance<File>(pos.square<KING>(WHITE), pos.square<KING>(BLACK))
                      - distance<Rank>(pos.square<KING>(WHITE), pos.square<KING>(BLACK));
 
-    bool infiltration =   rank_of(pos.square<KING>(WHITE)) > RANK_4
-                       || rank_of(pos.square<KING>(BLACK)) < RANK_5;
-
     bool pawnsOnBothFlanks =   (pos.pieces(PAWN) & QueenSide)
                             && (pos.pieces(PAWN) & KingSide);
 
@@ -715,15 +707,21 @@ namespace {
                            &&  outflanking < 0
                            && !pawnsOnBothFlanks;
 
+    bool infiltration = rank_of(pos.square<KING>(WHITE)) > RANK_4
+                     || rank_of(pos.square<KING>(BLACK)) < RANK_5;
+
     // Compute the initiative bonus for the attacking side
     int complexity =   9 * pe->passed_count()
                     + 11 * pos.count<PAWN>()
                     +  9 * outflanking
-                    + 12 * infiltration
                     + 21 * pawnsOnBothFlanks
+                    + 24 * infiltration
                     + 51 * !pos.non_pawn_material()
                     - 43 * almostUnwinnable
-                    - 100 ;
+                    -110 ;
+
+    Value mg = mg_value(score);
+    Value eg = eg_value(score);
 
     // Now apply the bonus: note that we find the attacking side by extracting the
     // sign of the midgame or endgame values, and that we carefully cap the bonus