If this data is correct, the probability of a high school athlete making it to the professional level is about 1 in 12,000. (I've heard that the probability is far more remote.) Baseball offers the most lucrative potential as well as the likelihood of having the longest career. But even that is estimated to be just three years for MLB. Doing the math, and discounting $400,000 per year for three years, beginning at age 17 and entering the big leagues at age 21 (not likely), the expected value of a career in baseball is about $86. Who's likely to pursue that?
The 78 percent number (i.e., 78% of NFL players go bankrupt within two years of retirement) is buoyed by the fact that the average NFL career lasts just three years. So, figure a player gets drafted in 2009, signs for the minimum and lasts three years in the league: He will have earned about $1.2 million in salary. Factor in taxes, cost of living and the misguided belief that there will be more years and bigger paydays down the road, and it becomes a lot easier to see how so many players struggle with money after their careers end.
Now, certainly it's not the average high school athlete who considers himself pro material, but It's still predominantly those with low opportunity costs of their time that pursue the professional athlete track. Even if we changed it so that a particular high school athlete was ten times more likely to make it to the professional level than the average high school athlete, the expected value is only about $860. That is total, not per year.
Making to the pros for many athletes is like the person winning the lottery who lives in a trailer - they've never learned how to handle the wealth.