In Harrington on Holdem vol 2, he discusses a concept which seems to be very common among pro tournament players. This concept is M, which is named for the guy who figured it out and I don't remember his name and the book is in my truck.
M is a ratio of your stack vs. the blinds.
If you have 6,000 chips early on and the blinds are 100/200, you have an M of 20. This puts you in what Harrington describes as the Green Zone. You're in great shape and can make some moves without too much concern. However, make a call and fold and you're immediately into the Yellow Zone, in which you have less room to maneuver.
Later, you've got 8,000TC and the blinds are 250/500 with an ante of 50. Now, the pot is 1200 and you've got an M of between 6 and 7--or you can play 6 more orbits before you're blinded out, as long as the blinds don't go up during that time. You're in the Orange Zone and you need to do something soon. You still have some fold equity for your all in, but not as much as you think.
You're up to 10,000TC and the blinds are 1000/2000 and antes are 50. The pot is 3450. Your M is less than 3--the Red Zone. Brother, you better push the first semi-decent hand that comes your way because you're about to be sent packing by the ever increasing blinds. You have 0 fold equity. People are just waiting for you to bust out. All in when you are first to bet, even with air. One more orbit and you're in the Dead Zone, where the blinds put you all in.
That's it, quick and dirty. It's something every tournament player must keep in mind during play. The blinds are the ever-increasing driving force and you must keep your M up if you're planning on being around for long. When the blind increases, you're M is cut in half, every time. Gather chips, gentleman, cause the blinds are coming at you from behind. Remember, too, that you're opponents also have an M, even if they aren't aware of it.
Every decision you make in a tournament is governed by your stack size, in relation to the blinds. How you play in each zone is where the debate begins.
More later, gotta go to work.
CJ
"Are the players better as the stakes go up? It's not an exam; it's a buyin." Barry Tanenbaum