Half the variations which are calculated in a tournament game turn out to be completely superfluous. Unfortunately, no one knows in advance which half.
If you are reading this instead of viewing a chess puzzle or game, then you must enable JavaScript on this website.
[Event "rated untimed match"]
[Site "?"]
[Date "1959.??.??"]
[Round "?"]
[White "Sallay"]
[Black "Barabash"]
[Result "0-1"]
[Annotator "David Hayes"]
[BlackElo "0"]
[FEN "r3k2r/ppp2ppp/3p4/3Np2n/2B1P2q/3P1P1b/PP2Rb1P/1RBQ3K b kq - 0 1"]
[SetUp "1"]
[TimeControl "0"]
[WhiteElo "0"]
1... Ng3+ 2. hxg3 Bg2+ 3. Kxg2 Qxg3+ 4. Kh1 ( { White can try: } 4. Kf1 Qg1# ) 4... Qh3# 0-1