Illegal Position Contest!

The only captured black pieces are the queen and c8 bishop. If the first move of the g2 pawn was to g3, the two dark square captures by the white pawns needed to let a black rook reach g2 could not happen. But the pawn must move before a white piece can be released to allow a black capture to release a piece for the pawn to capture, so the pawn had no first move.

Or the rook got in after h2-h4 but before g2-g3, which is illegal anyway because the rook can't jump over the pawns if no capture was made. Another try is the queen escaping via d8-b8-a7 to support cross-captures, but that means bBc8 was captured at home.

You probably knew this anyway. It's been hard making illegal positions, so I'm going to make these a bit easier. You could also contribute as I haven't seen you post one ever since I joined this thread.

The last move made was by the pawn at d4. The extra knight came from promoting the b7 pawn on c1, after the c2 pawn captured to d3 and the b2 pawn moved to let out the c1 bishop so the b7 pawn could capture to the c-file. But then the promoted knight had no escape from the promotion square.

Black's pawn capture was of White's only missing piece, the c1 bishop, but Pb2-b3 came first. Then for the black knight to reach c1 via d3, the white king and queen would have to move, after which the white queen would have no way to return to d1. 

White has no legal retraction to uncheck the black king.

repost

legal

This position was taken from one of my retros.

Bonus puzzle (original question from my retro): the position was reached via legal moves, but the piece on c6 is a spy and is something else. Can you prove its identity?

The piece on c6 is a white knight. If it were a black knight, White would lack enough light square captures for the c2 pawn to reach h7, since the c8 bishop has to be captured at home.

There are 7 black pieces that are missing after retracting e2-e3+ (if we had a black knight at c6). Although the bishops cannot get captured, there are still 5 pieces left (pawns can promote)

I'm not sure I understand that. If the knight on c6 is black instead of white, it sounds like you are counting the black a-pawn as a piece that can promote, but it clearly cannot. Black would have used four of its five captures (two by the pawn at h5, plus a rook and bishop on White's first rank) but the a-pawn would need two captures to promote.

Of course I get what you’re saying about the a pawn, but you haven’t specified about it last time. I like to be clearer and mention everything, and write a lot of retro-analysis. But next time, I’ll accept shorter answers (like yours).

I think you're right to ask for a complete explanation, and I only gave the main idea of the illegality proof. I mainly wanted to show with a proof game that the position could be legal with a white knight at c6.

Are there even judges here anymore

The white king.

Why illegal? Every square on the sixth rank is guarded by an unmoved black pawn, so the white king can never advance beyond the fifth rank.