In Arnold Snyder's book The Poker Tournament Formula, he writes in the first chapter about something called the Patience Factor. This term is a measure of how fast a tournament moves/blinds escalate compared to how many chips each player starts with. The lower the PF, the less skill is involved in winning the tournament; conversely, the higher the PF, the less luck comes into play and the more skill is required to go deep.
In short, his formula is essentially just the square of the so-called "blind-off" time; i.e., the time it would take to bust out due to blinding off, assuming you never played a single hand. For instance, let's assume we're going to play in a tournament with the following blind structure:
Assuming that each player began this tournament with T1000, we can see that somewhere between level 3 and 4, the cumulative cost of paying the blinds would exceed the initial stack size, and a player who was auto-mucking* would get blinded off at this point. Specifically, the player would get blinded off 1.3 hours into the tournament**. Squaring this figure*** gives us a PF of 1.6.
Once you have calculated the PF, you can estimate how much skill or luck a particular tournament will have in it, and therefore compare tourneys and find one best suited to your own abilities. Here's Snyder's chart that lists PF vs. Skill Level:
Note that this chart is only for live play; online play is significantly faster (read: more hands per hour). Per Snyder, the way to account for this is to multiply the online blind level time by the ratio of hands dealt per hour online to that of live. In other words, if we assume that the average hands per hour dealt online in a tournament is 50, and the average live is 30, then we multiple the online blind period by 50/30 to get an "adjusted" blind level period. This figure is then run through the spreadsheet and the new, adjusted PF can be plugged into the chart above to see how bad of a crapshoot the tourney is or isn't. Makes sense.
All-in for now...
*We're assuming here that the player never gets a walk in the big blind.
**I'll leave it to the reader to figure out for themselves how to do this calculation. It's pretty straightforward to do, and in fact I put it into a spreadsheet format so I can calculate different tourneys and compare them. You might consider doing the same.
***Snyder squares the tournament time to blind-off simply to make the differences between values more accentuated. Strange, but whatever.