- // 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 indexed by [rank]
- const Value ShelterWeakness[RANK_NB] =
- { V(100), V(0), V(27), V(73), V(92), V(101), V(101) };
-
- // Danger of enemy pawns moving toward our king indexed by
- // [no friendly pawn | pawn unblocked | pawn blocked][rank of enemy pawn]
- const Value StormDanger[][RANK_NB] = {
- { V( 0), V(64), V(128), V(51), V(26) },
- { V(26), V(32), V( 96), V(38), V(20) },
- { V( 0), V( 0), V(160), V(25), V(13) } };
-
- // 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(263);
+ // Pawn penalties
+ constexpr Score Isolated = S(13, 16);
+ constexpr Score Backward = S(17, 11);
+ constexpr Score Doubled = S(13, 40);
+
+ // Connected pawn bonus by opposed, phalanx, #support and rank
+ Score Connected[2][2][3][RANK_NB];
+
+ // 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(-13), V(83), V( 42), V(-27), V( 2), V(-32), V(-45) },
+ { V(-26), V(63), V( 5), V(-44), V( -5), V( 2), V(-59) },
+ { V(-19), V(53), V(-11), V(-22), V(-12), V(-51), V(-60) }
+ };
+
+ // 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.
+ constexpr Value UnblockedStorm[int(FILE_NB) / 2][RANK_NB] = {
+ { V( 25), V( 79), V(107), V( 51), V( 27), V( 0), V( 0) },
+ { V( 5), V( 35), V(121), V( -2), V( 15), V(-10), V(-10) },
+ { V(-20), V( 22), V( 98), V( 36), V( 7), V(-20), V(-20) },
+ { V(-27), V( 24), V( 80), V( 25), V( -4), V(-30), V(-30) }
+ };
+
+ // Danger of blocked enemy pawns storming our king, by rank
+ constexpr Value BlockedStorm[RANK_NB] =
+ { V( 0), V( 0), V( 75), V(-10), V(-20), V(-20), V(-20) };