So I'll try to explain as best as I understand it.
Firstly, the equation we use is WinRate - Std^2/(2*KellyFraction*Bankroll)
So your "Kelly Fraction" is essentially how we are going to define how "risky" you are as a person. The whole concept is, according to
wikipedia, " the guaranteed amount of money that an individual would view as equally desirable as a risky asset."
So what it means, is based on your individual kelly fraction (which quantifies your risk, based on how much of a RoR you'd accept), this will tell you if it's in your better interest to take a risky bet (i.e. a gamble), or a risk free bet (i.e. variance = 0).
Put it simply, for a given win rate, etc. of a game, and a given kelly fraction you play at, it would be better to take a job (we are defining a job as risk free) in which you are paid higher than your CE for the game you play.
So let's say you have a win rate of $50, and the CE is $30 (given your bankroll, kelly fraction, etc.) If somebody offered you a full time job for $25/hour, don't take it, because it's better to spend your time with a semi-risky $50/hour. But if they offered you a full time job for $35/hour, take it.