- // Isolated pawn penalty by opposed flag
- const Score Isolated[2] = { S(45, 40), S(30, 27) };
-
- // Backward pawn penalty by opposed flag
- 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
- const Score Doubled = S(18,38);
-
- // Lever bonus by rank
- const Score Lever[RANK_NB] = {
- S( 0, 0), S( 0, 0), S(0, 0), S(0, 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] = {
- { V( 97), V(21), V(26), V(51), V(87), V( 89), V( 99) },
- { V(120), V( 0), V(28), V(76), V(88), V(103), V(104) },
- { V(101), V( 7), V(54), V(78), V(77), V( 92), V(101) },
- { V( 80), V(11), V(44), V(68), V(87), V( 90), V(119) } };
-
- // Danger of enemy pawns moving toward our king by [type][distance from edge][rank]
- const Value StormDanger[][4][RANK_NB] = {
- { { V( 0), V( 67), V( 134), V(38), V(32) },
- { V( 0), V( 57), V( 139), V(37), V(22) },
- { V( 0), V( 43), V( 115), V(43), V(27) },
- { V( 0), V( 68), V( 124), V(57), V(32) } },
- { { V(20), V( 43), V( 100), V(56), V(20) },
- { V(23), V( 20), V( 98), V(40), V(15) },
- { V(23), V( 39), V( 103), V(36), V(18) },
- { V(28), V( 19), V( 108), V(42), V(26) } },
- { { V( 0), V( 0), V( 75), V(14), V( 2) },
- { V( 0), V( 0), V( 150), V(30), V( 4) },
- { V( 0), V( 0), V( 160), V(22), V( 5) },
- { V( 0), V( 0), V( 166), V(24), V(13) } },
- { { V( 0), V(-283), V(-281), V(57), V(31) },
- { V( 0), V( 58), V( 141), V(39), V(18) },
- { V( 0), V( 65), V( 142), V(48), V(32) },
- { V( 0), V( 60), V( 126), V(51), V(19) } } };
-
- // Max bonus for king safety. Corresponds to start position with all the pawns
- // in front of the king and no enemy pawn on the horizon.
- const Value MaxSafetyBonus = V(258);
+ // Pawn penalties
+ constexpr Score Backward = S( 9, 24);
+ constexpr Score BlockedStorm = S(82, 82);
+ constexpr Score Doubled = S(11, 56);
+ constexpr Score Isolated = S( 5, 15);
+ constexpr Score WeakLever = S( 0, 56);
+ constexpr Score WeakUnopposed = S(13, 27);
+
+ // Connected pawn bonus
+ constexpr int Connected[RANK_NB] = { 0, 7, 8, 12, 29, 48, 86 };
+
+ // Strength of pawn shelter for our king by [distance from edge][rank].
+ // RANK_1 = 0 is used for files where we have no pawn, or pawn is behind our king.
+ constexpr Value ShelterStrength[int(FILE_NB) / 2][RANK_NB] = {
+ { V( -6), V( 81), V( 93), V( 58), V( 39), V( 18), V( 25) },
+ { V(-43), V( 61), V( 35), V(-49), V(-29), V(-11), V( -63) },
+ { V(-10), V( 75), V( 23), V( -2), V( 32), V( 3), V( -45) },
+ { V(-39), V(-13), V(-29), V(-52), V(-48), V(-67), V(-166) }
+ };
+
+ // Danger of enemy pawns moving toward our king by [distance from edge][rank].
+ // RANK_1 = 0 is used for files where the enemy has no pawn, or their pawn
+ // is behind our king. Note that UnblockedStorm[0][1-2] accommodate opponent pawn
+ // on edge, likely blocked by our king.
+ constexpr Value UnblockedStorm[int(FILE_NB) / 2][RANK_NB] = {
+ { V( 85), V(-289), V(-166), V(97), V(50), V( 45), V( 50) },
+ { V( 46), V( -25), V( 122), V(45), V(37), V(-10), V( 20) },
+ { V( -6), V( 51), V( 168), V(34), V(-2), V(-22), V(-14) },
+ { V(-15), V( -11), V( 101), V( 4), V(11), V(-15), V(-29) }
+ };