- 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);
+ 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) } }
+ };