Compose a position where
- It's White to move
- White can deliver checkmate or stalemate in 1 move
- Or if they make a different move, then Black can deliver checkmate or stalemate in one 1 move
I needed 6 white pieces and 11 black pieces. Beat me!
Toned down example for understanding:
[FEN "7k/7P/7K/6BP/8/8/8/8 w - - 0 0"]
After the next White move, Black is either mated or stalemated, depending on if White plays Bf6 or not. (This does not meet the 3rd requirement).