‘What position you’re sitting in at the table also plays a big role in deciding what hands you should and shouldn’t play. Because the player on the button is the last to act on all rounds after the initial preflop betting round, that player has a decided advantage over everyone else at the table. As we said before, the player on the button gets to see what everyone else is going to do before he has to make any decisions of his own. Because of this, the player on the button can play a wider variety of hands than players in other positions.
Players in earlier positions to the button have to decide if they want to bet, fold, raise, or check before they’ve seen what the rest of the table is going to do. If a player in first position (the first player to act in the postflop betting rounds) has pocket sevens but an ace or a king comes on the flop, it would be unsafe to bet out of fear that someone with a high card has made a better pair. The player with pocket sevens might get reraised and thus have no choice but to abandon his initial raise and lose the money he has already invested. On the other hand, the player on the button with pocket sevens can easily raise the pot on the same flop if no one has yet made a bet.
The rule of position is as follows: The closer you are to the right of the button, the wider the variety of hands it is safe to play. Better position means more information, and more information means more power.