Chess Opening Theory/1. f4/1...e5/2. fxe5/2...d6/3. exd6/3...Bxd6/4. h4/4...Bg3

Bird's Opening
	a b c d e f g h 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 a b c d e f g h
	Position in Forsyth-Edwards Notation (FEN) rnbqk1nr/ppp2ppp/8/8/7P/6b1/PPPPP1P1/RNBQKBNR w
	Moves: 1. f4 e5 2. fxe5 d6 3. exd6 Bxd6 4. h4 Bg3

4...Bg3#

This unexpected move checkmates the white king along the e1-h4 diagonal in a resounding fashion.

1.f4 e5 2.fxe5 d6 3.exd6 Bxd6 4.h4?? Bg3#

Bird's Opening
a b c d e f g h 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1 a b c d e f g h
Position in Forsyth-Edwards Notation (FEN) rnbqk1nr/ppp2ppp/8/8/7P/6b1/PPPPP1P1/RNBQKBNR w
Moves: 1. f4 e5 2. fxe5 d6 3. exd6 Bxd6 4. h4 Bg3