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 "????.??.??"]
[Round "?"]
[White "Unknown"]
[Black "Unknown455"]
[Result "1-0"]
[Annotator "David Hayes"]
[BlackElo "0"]
[FEN "3r2k1/ppQ1qppp/2p5/8/Pb6/4P2P/BP4P1/5R1K w - - 0 1"]
[SetUp "1"]
[TimeControl "0"]
[WhiteElo "0"]
{ A classic discovery attack. } 1. Qxe7 Bxe7 2. Rxf7 Bg5 3. Rf5+ Kh8 4. Rxg5 { White wins with a large material advantage. } 1-0