- // Doubled pawn penalty by file
- const Score Doubled[FILE_NB] = {
- S(13, 43), S(20, 48), S(23, 48), S(23, 48),
- S(23, 48), S(23, 48), S(20, 48), S(13, 43) };
-
- // Isolated pawn penalty by opposed flag and file
- const Score Isolated[2][FILE_NB] = {
- { S(37, 45), S(54, 52), S(60, 52), S(60, 52),
- S(60, 52), S(60, 52), S(54, 52), S(37, 45) },
- { S(25, 30), S(36, 35), S(40, 35), S(40, 35),
- S(40, 35), S(40, 35), S(36, 35), S(25, 30) } };
-
- // Backward pawn penalty by opposed flag and file
- const Score Backward[2][FILE_NB] = {
- { S(30, 42), S(43, 46), S(49, 46), S(49, 46),
- S(49, 46), S(49, 46), S(43, 46), S(30, 42) },
- { S(20, 28), S(29, 31), S(33, 31), S(33, 31),
- S(33, 31), S(33, 31), S(29, 31), S(20, 28) } };
-
- // Connected pawn bonus by opposed, phalanx flags and rank
- Score Connected[2][2][RANK_NB];
-
- // Levers bonus by rank
- const Score Lever[RANK_NB] = {
- S( 0, 0), S( 0, 0), S(0, 0), S(0, 0),
- S(20,20), S(40,40), S(0, 0), S(0, 0) };
-
- // Unsupported pawn penalty
- const Score UnsupportedPawnPenalty = S(20, 10);
-
- // Weakness of our pawn shelter in front of the king by [distance from edge][rank]
- const Value ShelterWeakness[][RANK_NB] = {
- { V( 99), V(20), V(26), V(54), V(85), V( 92), V(108) },
- { V(117), V( 1), V(27), V(71), V(94), V(104), V(118) },
- { V(104), V( 4), V(51), V(76), V(82), V(102), V( 97) },
- { V( 80), V(12), V(43), V(65), V(88), V( 91), V(115) } };
-
- // Danger of enemy pawns moving toward our king by [type][distance from edge][rank]
- const Value StormDanger[][4][RANK_NB] = {
- { { V( 0), V( 65), V( 126), V(36), V(30) },
- { V( 0), V( 55), V( 135), V(36), V(23) },
- { V( 0), V( 47), V( 116), V(45), V(26) },
- { V( 0), V( 62), V( 127), V(57), V(34) } },
- { { V(21), V( 45), V( 93), V(50), V(19) },
- { V(23), V( 24), V( 105), V(41), V(13) },
- { V(23), V( 36), V( 101), V(38), V(20) },
- { V(30), V( 19), V( 110), V(41), V(27) } },
- { { V( 0), V( 0), V( 81), V(14), V( 4) },
- { V( 0), V( 0), V( 169), V(30), V( 3) },
- { V( 0), V( 0), V( 168), V(24), V( 5) },
- { V( 0), V( 0), V( 162), V(26), V(10) } },
- { { V( 0), V(-283), V(-298), V(57), V(29) },
- { V( 0), V( 63), V( 137), V(42), V(18) },
- { V( 0), V( 67), V( 145), V(49), V(33) },
- { V( 0), V( 62), V( 126), V(53), V(21) } } };
-
- // 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);
+ // Isolated pawn penalty
+ constexpr Score Isolated = S(13, 16);
+
+ // Backward pawn penalty
+ constexpr Score Backward = S(17, 11);
+
+ // Connected pawn bonus by opposed, phalanx, #support and rank
+ Score Connected[2][2][3][RANK_NB];
+
+ // Doubled pawn penalty
+ constexpr Score Doubled = S(13, 40);
+
+ // 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( 7), V(76), V(84), V( 38), V( 7), V( 30), V(-19) },
+ { V(-3), V(93), V(52), V(-17), V(12), V(-22), V(-35) },
+ { V(-6), V(83), V(25), V(-24), V(15), V( 22), V(-39) },
+ { V(11), V(83), V(19), V( 8), V(18), V(-21), V(-30) }
+ };
+
+ // Danger of enemy pawns moving toward our king by [type][distance from edge][rank].
+ // For the unblocked case, RANK_1 = 0 is used when opponent has no pawn on the
+ // given file, or their pawn is behind our king.
+ constexpr Value StormDanger[][4][RANK_NB] = {
+ { { V(25), V( 79), V(107), V( 51), V( 27) }, // UnBlocked
+ { V(15), V( 45), V(131), V( 8), V( 25) },
+ { V( 0), V( 42), V(118), V( 56), V( 27) },
+ { V( 3), V( 54), V(110), V( 55), V( 26) } },
+ { { V( 0), V( 0), V( 37), V( 5), V(-48) }, // BlockedByPawn
+ { V( 0), V( 0), V( 68), V(-12), V( 13) },
+ { V( 0), V( 0), V(111), V(-25), V( -3) },
+ { V( 0), V( 0), V(108), V( 14), V( 21) } }
+ };