Simplify unstoppable pawns

[stockfish] / src / evaluate.cpp

diff --git a/src/evaluate.cpp b/src/evaluate.cpp
index 804e1dd780dc58c033aaf87f7fec503b71d5b4ba..1099a6e40b57a58e85f608d79e2857dba834faa1 100644 (file)
--- a/src/evaluate.cpp
+++ b/src/evaluate.cpp
@@ -76,7 +76,7 @@ namespace {
   namespace Tracing {
 
     enum Terms { // First 8 entries are for PieceType
-      PST = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, TOTAL, TERMS_NB
+      MATERIAL = 8, IMBALANCE, MOBILITY, THREAT, PASSED, SPACE, TOTAL, TERMS_NB
     };
 
     Score terms[COLOR_NB][TERMS_NB];
@@ -147,7 +147,7 @@ namespace {
   // ThreatenedByPawn[PieceType] contains a penalty according to which piece
   // type is attacked by an enemy pawn.
   const Score ThreatenedByPawn[] = {
-    S(0, 0), S(0, 0), S(56, 70), S(56, 70), S(76, 99), S(86, 118)
+    S(0, 0), S(0, 0), S(80, 119), S(80, 119), S(117, 199), S(127, 218)
   };
 
   // Hanging contains a bonus for each enemy hanging piece
@@ -231,10 +231,10 @@ namespace {
   }
 
 
-  // evaluate_outposts() evaluates bishop and knight outpost squares
+  // evaluate_outpost() evaluates bishop and knight outpost squares
 
   template<PieceType Pt, Color Us>
-  Score evaluate_outposts(const Position& pos, EvalInfo& ei, Square s) {
+  Score evaluate_outpost(const Position& pos, const EvalInfo& ei, Square s) {
 
     const Color Them = (Us == WHITE ? BLACK : WHITE);
 
@@ -315,9 +315,9 @@ namespace {
             if (Pt == BISHOP)
                 score -= BishopPawns * ei.pi->pawns_on_same_color_squares(Us, s);
 
-            // Bishop and knight outposts squares
+            // Bishop and knight outpost square
             if (!(pos.pieces(Them, PAWN) & pawn_attack_span(Us, s)))
-                score += evaluate_outposts<Pt, Us>(pos, ei, s);
+                score += evaluate_outpost<Pt, Us>(pos, ei, s);
 
             // Bishop or knight behind a pawn
             if (    relative_rank(Us, s) < RANK_5
@@ -506,7 +506,7 @@ namespace {
     // Add a bonus according if the attacking pieces are minor or major
     if (weakEnemies)
     {
-        b = weakEnemies & (ei.attackedBy[Us][PAWN] | ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
+        b = weakEnemies & (ei.attackedBy[Us][KNIGHT] | ei.attackedBy[Us][BISHOP]);
         if (b)
             score += Threat[0][type_of(pos.piece_on(lsb(b)))];
 
@@ -613,17 +613,14 @@ namespace {
 
 
   // evaluate_unstoppable_pawns() scores the most advanced among the passed and
-  // candidate pawns. In case opponent has no pieces but pawns, this is somewhat
-  // related to the possibility that pawns are unstoppable.
+  // candidate pawns. In case both players have no pieces but pawns, this is
+  // somewhat related to the possibility that pawns are unstoppable.
 
-  Score evaluate_unstoppable_pawns(const Position& pos, Color us, const EvalInfo& ei) {
+  Score evaluate_unstoppable_pawns(Color us, const EvalInfo& ei) {
 
     Bitboard b = ei.pi->passed_pawns(us) | ei.pi->candidate_pawns(us);
 
-    if (!b || pos.non_pawn_material(~us))
-        return SCORE_ZERO;
-
-    return Unstoppable * int(relative_rank(us, frontmost_sq(us, b)));
+    return b ? Unstoppable * int(relative_rank(us, frontmost_sq(us, b))) : SCORE_ZERO;
   }
 
 
@@ -716,10 +713,10 @@ namespace {
     score +=  evaluate_passed_pawns<WHITE, Trace>(pos, ei)
             - evaluate_passed_pawns<BLACK, Trace>(pos, ei);
 
-    // If one side has only a king, score for potential unstoppable pawns
-    if (!pos.non_pawn_material(WHITE) || !pos.non_pawn_material(BLACK))
-        score +=  evaluate_unstoppable_pawns(pos, WHITE, ei)
-                - evaluate_unstoppable_pawns(pos, BLACK, ei);
+    // If both sides have only pawns, score for potential unstoppable pawns
+    if (!pos.non_pawn_material(WHITE) && !pos.non_pawn_material(BLACK))
+        score +=  evaluate_unstoppable_pawns(WHITE, ei)
+                - evaluate_unstoppable_pawns(BLACK, ei);
 
     // Evaluate space for both sides, only in middlegame
     if (ei.mi->space_weight())
@@ -763,7 +760,7 @@ namespace {
     // In case of tracing add all single evaluation contributions for both white and black
     if (Trace)
     {
-        Tracing::add_term(Tracing::PST, pos.psq_score());
+        Tracing::add_term(Tracing::MATERIAL, pos.psq_score());
         Tracing::add_term(Tracing::IMBALANCE, ei.mi->material_value());
         Tracing::add_term(PAWN, ei.pi->pawns_value());
         Tracing::add_term(Tracing::MOBILITY, apply_weight(mobility[WHITE], Weights[Mobility])
@@ -796,13 +793,13 @@ namespace {
     Score bScore = terms[BLACK][idx];
 
     switch (idx) {
-    case PST: case IMBALANCE: case PAWN: case TOTAL:
-        ss << std::setw(20) << name << " |   ---   --- |   ---   --- | "
+    case MATERIAL: case IMBALANCE: case PAWN: case TOTAL:
+        ss << std::setw(15) << name << " |   ---   --- |   ---   --- | "
            << std::setw(5)  << to_cp(mg_value(wScore - bScore)) << " "
            << std::setw(5)  << to_cp(eg_value(wScore - bScore)) << " \n";
         break;
     default:
-        ss << std::setw(20) << name << " | " << std::noshowpos
+        ss << std::setw(15) << name << " | " << std::noshowpos
            << std::setw(5)  << to_cp(mg_value(wScore)) << " "
            << std::setw(5)  << to_cp(eg_value(wScore)) << " | "
            << std::setw(5)  << to_cp(mg_value(bScore)) << " "
@@ -821,12 +818,12 @@ namespace {
 
     std::stringstream ss;
     ss << std::showpoint << std::noshowpos << std::fixed << std::setprecision(2)
-       << "           Eval term |    White    |    Black    |    Total    \n"
-       << "                     |   MG    EG  |   MG    EG  |   MG    EG  \n"
-       << "---------------------+-------------+-------------+-------------\n";
+       << "      Eval term |    White    |    Black    |    Total    \n"
+       << "                |   MG    EG  |   MG    EG  |   MG    EG  \n"
+       << "----------------+-------------+-------------+-------------\n";
 
-    format_row(ss, "Material, PST", PST);
-    format_row(ss, "Material imbalance", IMBALANCE);
+    format_row(ss, "Material", MATERIAL);
+    format_row(ss, "Imbalance", IMBALANCE);
     format_row(ss, "Pawns", PAWN);
     format_row(ss, "Knights", KNIGHT);
     format_row(ss, "Bishops", BISHOP);
@@ -838,7 +835,7 @@ namespace {
     format_row(ss, "Passed pawns", PASSED);
     format_row(ss, "Space", SPACE);
 
-    ss << "---------------------+-------------+-------------+-------------\n";
+    ss << "----------------+-------------+-------------+-------------\n";
     format_row(ss, "Total", TOTAL);
 
     ss << "\nTotal Evaluation: " << to_cp(v) << " (white side)\n";
@@ -855,7 +852,7 @@ namespace Eval {
   /// of the position always from the point of view of the side to move.
 
   Value evaluate(const Position& pos) {
-    return do_evaluate<false>(pos);
+    return do_evaluate<false>(pos) + Tempo;
   }