This is a discussion on What is TAG? within the online poker forums, in the Learning Poker section; In Phil Hellmuth's book on NL Holdem Tournaments:
TAG = Tight Aggressive
This is a perfect strategy for playing early stages of the tournament, because loose players
This is a perfect strategy for playing early stages of the tournament, because loose players will try to play draws on you, when you have the advantage with overpairs or sets. Sometimes you'll have them crushed on a two diamond board and you have AKd and they have lets say 67d or something. So it is worth it to stay patient.
The biggest weakness to this strategy, however, (this wasn't mentioned in Phil's book) is:
PLAY IN POSITION.
If that means folding some hands like QJ A10 AJ in early position, then that's what you must do, otherwise YOU WILL BE EXPLOITED BASED ON RANGE. They will put you on medium pairs or broadway hands (Paint Cards), and they will try to play those 67s 89s J10s in position and just barrel away at you when your hand is susceptible to loosing to the nuts.
I do agree you should play in position more than you play out of position, but I see 2 issues with your statement
1) You really cant be very picky in a tournament as you can easily end up as a short stack after a hand if you wait for the best cards in the best position, also if you fold so much in early position, others can easily know that when you raise you have the nuts.
2) Unlike a cash game where you will be playing with the same people all day, in a tournament your table might change and people will get eliminated, so reads kind of matter less as you wont be playing with the same people long enough to get a decent read unless you keep playing the same style with the same person until deep stages in a tournament.