Kelly Criterion, ROI, and Staking

[ike]

If you're not familiar with Kelly Criterion calculations, read this before continuing:

http://en.wikipedia.org/wiki/Kelly_criterion

It seems like something very much like this could be a very useful tool to MTT players/backers. Having an analytic way to calculate how much of your own action you want to sell in a big tournament or how much of other players action you want to buy would be awesome. The problem is that the Kelly Criterion math I've seen assumes you get paid X : 1 on your bet and win Y% of the time. How can I adapt this to the much more complicated payoff distribution of an MTT?