+ // Do not include in mobility squares protected by enemy pawns or occupied by our pawns or king
+ Bitboard mobilityArea[] = { ~(ei.attackedBy[BLACK][PAWN] | pos.pieces(WHITE, PAWN, KING)),
+ ~(ei.attackedBy[WHITE][PAWN] | pos.pieces(BLACK, PAWN, KING)) };
+
+ // Evaluate pieces and mobility
+ score += evaluate_pieces<KNIGHT, WHITE, Trace>(pos, ei, mobility, mobilityArea);
+ score += apply_weight(mobility[WHITE] - mobility[BLACK], Weights[Mobility]);
+
+ // Evaluate kings after all other pieces because we need complete attack
+ // information when computing the king safety evaluation.
+ score += evaluate_king<WHITE, Trace>(pos, ei)
+ - evaluate_king<BLACK, Trace>(pos, ei);
+
+ // Evaluate tactical threats, we need full attack information including king
+ score += evaluate_threats<WHITE, Trace>(pos, ei)
+ - evaluate_threats<BLACK, Trace>(pos, ei);
+
+ // Evaluate passed pawns, we need full attack information including king
+ 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);
+
+ // Evaluate space for both sides, only in middlegame
+ if (ei.mi->space_weight())
+ {
+ int s = evaluate_space<WHITE>(pos, ei) - evaluate_space<BLACK>(pos, ei);
+ score += apply_weight(s * ei.mi->space_weight(), Weights[Space]);
+ }
+
+ // Scale winning side if position is more drawish than it appears
+ ScaleFactor sf = eg_value(score) > VALUE_DRAW ? ei.mi->scale_factor(pos, WHITE)
+ : ei.mi->scale_factor(pos, BLACK);
+
+ // If we don't already have an unusual scale factor, check for opposite
+ // colored bishop endgames, and use a lower scale for those.
+ if ( ei.mi->game_phase() < PHASE_MIDGAME
+ && pos.opposite_bishops()
+ && (sf == SCALE_FACTOR_NORMAL || sf == SCALE_FACTOR_ONEPAWN))
+ {
+ // Ignoring any pawns, do both sides only have a single bishop and no
+ // other pieces?
+ if ( pos.non_pawn_material(WHITE) == BishopValueMg
+ && pos.non_pawn_material(BLACK) == BishopValueMg)
+ {
+ // Check for KBP vs KB with only a single pawn that is almost
+ // certainly a draw or at least two pawns.
+ bool one_pawn = (pos.count<PAWN>(WHITE) + pos.count<PAWN>(BLACK) == 1);
+ sf = one_pawn ? ScaleFactor(8) : ScaleFactor(32);
+ }
+ else
+ // Endgame with opposite-colored bishops, but also other pieces. Still
+ // a bit drawish, but not as drawish as with only the two bishops.
+ sf = ScaleFactor(50 * sf / SCALE_FACTOR_NORMAL);
+ }
+
+ // Interpolate between a middlegame and an endgame score, scaling by 'sf'
+ Value v = mg_value(score) * int(ei.mi->game_phase())
+ + eg_value(score) * int(sf) / SCALE_FACTOR_NORMAL * int(PHASE_MIDGAME - ei.mi->game_phase());
+
+ v /= PHASE_MIDGAME;
+
+ // 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::IMBALANCE, ei.mi->material_value());
+ Tracing::add_term(PAWN, ei.pi->pawns_value());
+ Tracing::add_term(Tracing::MOBILITY, apply_weight(mobility[WHITE], Weights[Mobility])
+ , apply_weight(mobility[BLACK], Weights[Mobility]));
+ Score w = ei.mi->space_weight() * evaluate_space<WHITE>(pos, ei);
+ Score b = ei.mi->space_weight() * evaluate_space<BLACK>(pos, ei);
+ Tracing::add_term(Tracing::SPACE, apply_weight(w, Weights[Space]), apply_weight(b, Weights[Space]));
+ Tracing::add_term(Tracing::TOTAL, score);
+ Tracing::ei = ei;
+ Tracing::sf = sf;
+ }
+
+ return pos.side_to_move() == WHITE ? v : -v;