When you’re playing tournament poker, you will be confronted now and then with the phenomenon of shorthanded poker. Because more and more players will get eliminated, the number of players sitting down at the table will decrease each time somebody leaves. You have to switch gears at those moments, because you’re playing a totally different game from now on: shorthanded poker.

Basically, you can recapitulate the essence of shorthanded poker in one sentence: play more aggressively.  On the one hand because your own hand increases in value (there are less hands to beat) and on the other hand because the other players will play more aggressively because they also realize this fact. This was perfectly demonstrated by Phil Hellmuth on Poker After Dark (after 1’20″):

Phil limps from the small blind with an ace. So why do that if your hand increases in value during a shorthanded game? Because he has won 11 WSOP bracelets and knows that Jean Robert Bellande, who was playing fairly aggressive, also realizes his hand increased in value. So Phil knew Bellande was going to make a move again when he would pick up something and raises all-in instantly. Good play from the master.