Illegal Position Contest!

Bro

Legal

As you already know, white has enough expendable pieces to allow for black to set up the pawns. Adding any additional white piece to the position will make it illegal.

No one has commented on KieferSmith's position at #7611. Is that because people thought it was too easy to bother with? (Black has made 12 pawn captures, but White is only missing 11 units.) Plenty of more obvious illegalities have shown up here, like a recent one with no black king on the board.

In order for a white pawn to "pass by" a black pawn or vice versa, it must make a capture to change files. But nothing has been captured.

White must make two captures to set up the pawn structure. Black is missing two pieces, consisting of a pawn and a dark squared bishop. However, the dark squared bishop would not have been able to leave its home square and must have been captured there, so there are not enough captures for white to set up the pawns.

wow there is a lot of comments

got it from 5733 of spg

Illegal check

Thanks nice work!!!

Too easy.

this one feels legal

but i dont know

Turns out this position is illegal:

It's legal if it's a Rook on b3 and a pawn on c2, but not the other way around.