One of the greatest inventions in the history of chess was the chess clock. A chess player has to make all of his moves in a given amount of time or forfeit.
There's a type of sudden-death time control called "armageddon" that is used as the final tie-break even in world championships. White gets 5 minutes and Black gets 4 minutes for the entire game. Black has draw odds though. If White doesn't checkmate in time, he loses the match. I've played in and seen armageddon games where White needed just one more move to deliver checkmate but the flag was called first.
If both sides agree to play with a certain time control, then a game decided by the clock is fair.
Why does beating somebody by time vs checkmate seem like cheating? Anybody else feel this way?