Penalize doubled pawns (+23 tokens)

Score of Dev vs Main: 357 - 281 - 441  [0.535] 1079
...      Dev playing White: 178 - 141 - 220  [0.534] 539
...      Dev playing Black: 179 - 140 - 221  [0.536] 540
...      White vs Black: 318 - 320 - 441  [0.499] 1079
Elo difference: 24.5 +/- 15.9, LOS: 99.9 %, DrawRatio: 40.9 %
SPRT: llr 2.96 (100.4%), lbound -2.94, ubound 2.94 - H1 was accepted

Chess-Challenge/src/My Bot/MyBot.cs

@@ -151,9 +151,11 @@ int AlphaBeta(int depth, int alpha, int beta, bool nullMoveAllowed = true, bool
                     ulong bitboard = board.GetPieceBitboard((PieceType)piece + 1, xor is 56);
                     while (bitboard != 0)
                     {
-                        int index = piece +                                          // piece index
-                            16 * (BitboardHelper.ClearAndGetIndexOfLSB(ref bitboard) // row of square
-                            ^ xor);                                                  // flip board for white pieces
+                        int square = BitboardHelper.ClearAndGetIndexOfLSB(ref bitboard) ^ xor;
+                        int index = piece + 16 * square;
+
+                        if (piece == 0 && (0x101010101010101UL << (square & 7) & bitboard) > 0)
+                            egScore -= 9;
 
                         mgScore += pieceSquareTables[index];
                         egScore += pieceSquareTables[index + 6];