[Event "?"]
[Site "?"]
[Date "????.??.??"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[SetUp "1"]
[FEN "r5k1/Qb2bppp/p1q2n2/2p1p3/P7/1PB5/2P2PPP/3RR1K1 w - - 0 1"]
[PlyCount "4"]
{} 1. Qxa8+ {and black tried to play Qxg2#. Black immediately left the
board to mark his result. Upon returning, he learned that his checkmate is
illegal, and he touched his queen. Thus resulting in a move less favorable
than ...Bxa8.} Qc8 (1... Bxa8) 2. Qxc8+ Bxc8 *