Instead of copying the centre, the reply comes from the side. Both kings come under fire early, so one slip decides it. Of the four central squares, pawns stand on e4. 2 pieces have left the board. Black has castled.
The position
Length
16 moves
To move
White
Legal replies
45
Minor pieces out
White 3 · Black 3
Material
level
Castling rights left
KQ
FEN
r1bq1rk1/pp2ppbp/2np1np1/8/3NP3/2N1BP2/PPPQ2PP/R3KB1R w KQ - 3 9
Move by move
Each move spelled out: which piece went from where to where.