- // 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 file and rank (initialized by formula)
- Score Connected[FILE_NB][RANK_NB];
-
- // Candidate passed pawn bonus by rank
- const Score CandidatePassed[RANK_NB] = {
- S( 0, 0), S( 6, 13), S(6,13), S(14,29),
- S(34,68), S(83,166), S(0, 0), S( 0, 0) };
-
- // Bonus for file distance of the two outermost pawns
- const Score PawnsFileSpan = S(0, 15);
-
- // 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[3][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) } };
+ // Isolated pawn penalty
+ const Score Isolated = S(13, 18);
+
+ // Backward pawn penalty
+ const Score Backward = S(24, 12);
+
+ // Connected pawn bonus by opposed, phalanx, #support and rank
+ Score Connected[2][2][3][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 [isKingFile][distance from edge][rank].
+ // RANK_1 = 0 is used for files where we have no pawns or our pawn is behind our king.
+ const Value ShelterWeakness[][int(FILE_NB) / 2][RANK_NB] = {
+ { { V( 97), V(17), V( 9), V(44), V( 84), V( 87), V( 99) }, // Not On King file
+ { V(106), V( 6), V(33), V(86), V( 87), V(104), V(112) },
+ { V(101), V( 2), V(65), V(98), V( 58), V( 89), V(115) },
+ { V( 73), V( 7), V(54), V(73), V( 84), V( 83), V(111) } },
+ { { V(104), V(20), V( 6), V(27), V( 86), V( 93), V( 82) }, // On King file
+ { V(123), V( 9), V(34), V(96), V(112), V( 88), V( 75) },
+ { V(120), V(25), V(65), V(91), V( 66), V( 78), V(117) },
+ { V( 81), V( 2), V(47), V(63), V( 94), V( 93), V(104) } }
+ };
+
+ // Danger of enemy pawns moving toward our king by [type][distance from edge][rank].
+ // For the unopposed and unblocked cases, RANK_1 = 0 is used when opponent has
+ // no pawn on the given file, or their pawn is behind our king.
+ const Value StormDanger[][4][RANK_NB] = {
+ { { V( 0), V(-290), V(-274), V(57), V(41) }, // BlockedByKing
+ { V( 0), V( 60), V( 144), V(39), V(13) },
+ { V( 0), V( 65), V( 141), V(41), V(34) },
+ { V( 0), V( 53), V( 127), V(56), V(14) } },
+ { { V( 4), V( 73), V( 132), V(46), V(31) }, // Unopposed
+ { V( 1), V( 64), V( 143), V(26), V(13) },
+ { V( 1), V( 47), V( 110), V(44), V(24) },
+ { V( 0), V( 72), V( 127), V(50), V(31) } },
+ { { V( 0), V( 0), V( 79), V(23), V( 1) }, // BlockedByPawn
+ { V( 0), V( 0), V( 148), V(27), V( 2) },
+ { V( 0), V( 0), V( 161), V(16), V( 1) },
+ { V( 0), V( 0), V( 171), V(22), V(15) } },
+ { { V(22), V( 45), V( 104), V(62), V( 6) }, // Unblocked
+ { V(31), V( 30), V( 99), V(39), V(19) },
+ { V(23), V( 29), V( 96), V(41), V(15) },
+ { V(21), V( 23), V( 116), V(41), V(15) } }
+ };