Illegal Position Contest!

I wished I had more space on the board.

Continued from post #497.

Quite a funny example. All the 16 pawns cannot cross safely to the enemies' respective sides without making captures.

yeah smurfisme it is. the last move was X. ..Kc8

It took me quite some time to realise that the position in post #501 is illegal.

You wrote this on a chat box, right? Now, somewhere just above the chat box, you see many small icons. The left-most of the icons appears like a chess board. Click on it, and that is where you can post games or set up random positions.

How is post 501's position illegal? Is it unreachable by move order? That's the only thing I haven't checked. Or maybe there's something I'm missing.

If you notice carefully, there are two things to consider.

First, look at which pieces are missing from the board. Only the dark-squared black bishop and a white knight, but this white knight is not important. Next, look at white's pawn structure. How did the f3 pawn get there? Well, the e2 and f2 pawns remain there from the start, so the only way this could happen is that the g2 pawn makes a capture on f3, and both g2 and f3 are on light-squares.

Since the only missing black piece is the dark squared bishop, that must be the piece captured. And the fact that the g2 pawn moves to f3 indicates that a capture must have been made by the pawn. But how does the pawn capture the bishop?

blacks dark squared bishop is missing and whites knight. the only way the pawn can go to f3 is via gxf3 and the only piece that the pawn could've taken is the dark squared bishop but because f3 is a light square the position is illegal.

OOOOOOOOOOOOOOOOOOOOOOOOOOOHHHHHHHHHHHHHHHHHHh

what won't work?