I'm writing a chess engine just for fun, and during the validation of movement generation, I found some positions in Perft Results that differ from what my engine is producing.
As an example, take the below position.
[FEN "r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq - 0 1"]
I found in the Chess programming wiki, the number of possible positions in depth 5 is 193690690, and my program matches this value.
However, regarding the number of possible double checks, my program found 8 more positions. The Perft Results from the Wiki indicate a total of 2637, while I found 2645.
I don't know what to think. Maybe the Perft Result from the Wiki does not consider positions where a pawn promotes with check whilst revealing a check, aka a discovered check. But there are only 6 moves where a pawn promotion results in a double check (3 positions, where the pawn may promote to queen or rook). Are the positions from Wiki wrong?
If someone wants to look at the positions, they can be found here on Google Drive.