Actually I use Kelly criterion to size my own positions. Rather than go into a long disertation I will simply say that to use it effectively you have to be able to characterize the trade in one of two ways;
1. Percentage of risk that you are willing to accept in the form of drawdown
2. The nature of your edge expressed as a percentage or "confidence" factor. i.e. you evaluate the odds of success at 80%.
In theory if you had a 100% confidence in your success, you would put on a trade using 100% of your account value.
In practice, most traders using a fractional method and call themselves 50% Kelly Traders, or 75% Kelly Traders....
Do you see what I am saying?
If you would like more information, and a specific contact you may PM me.
Good luck,
Steve