constexpr Score WeakLever = S( 0, 56);
constexpr Score WeakUnopposed = S(13, 27);
- constexpr Score BlockedStorm[RANK_NB] = {S( 0, 0), S( 0, 0), S( 76, 78), S(-10, 15), S(-7, 10), S(-4, 6), S(-1, 2)};
+ // Bonus for blocked pawns at 5th or 6th rank
+ constexpr Score BlockedPawn[2] = { S(-11, -4), S(-3, 4) };
+
+ constexpr Score BlockedStorm[RANK_NB] = {
+ S(0, 0), S(0, 0), S(76, 78), S(-10, 15), S(-7, 10), S(-4, 6), S(-1, 2)
+ };
// Connected pawn bonus
constexpr int Connected[RANK_NB] = { 0, 7, 8, 12, 29, 48, 86 };
#undef S
#undef V
+
+ /// evaluate() calculates a score for the static pawn structure of the given position.
+ /// We cannot use the location of pieces or king in this function, as the evaluation
+ /// of the pawn structure will be stored in a small cache for speed reasons, and will
+ /// be re-used even when the pieces have moved.
+
template<Color Us>
Score evaluate(const Position& pos, Pawns::Entry* e) {
// Score this pawn
if (support | phalanx)
{
- int v = Connected[r] * (4 + 2 * bool(phalanx) - 2 * bool(opposed) - bool(blocked)) / 2
+ int v = Connected[r] * (2 + bool(phalanx) - bool(opposed))
+ 21 * popcount(support);
score += make_score(v, v * (r - 2) / 4);
if (!support)
score -= Doubled * doubled
+ WeakLever * more_than_one(lever);
+
+ if (blocked && r > RANK_4)
+ score += BlockedPawn[r-4];
}
return score;
namespace Pawns {
+
/// Pawns::probe() looks up the current position's pawns configuration in
/// the pawns hash table. It returns a pointer to the Entry if the position
/// is found. Otherwise a new Entry is computed and stored there, so we don't