Yesterday, Mark Buehrle of the Chicago White Sox pitched a perfect game — only the 18th in the 133-year history of big-league baseball.

This masterpiece added to lustre to a resume that seems to grow in stature every year. Buehrle pitched a no-hitter in 2007, won a World Series title, and was the winning pitcher in the All-Star Game. He has spent a decade in the major leagues, and has won 133 games, far more than the average pitcher.

It has been, by any measure, an above-average career.

So here’s the question: When Buehrle was in high school, and being scouted by big-league teams, how was he viewed? When top-level talent scouts came to see him, what was their opinion of his ability and potential?

To find the answer, simply look at the 1998 draft. Buehrle was selected in the 38th round. That means that well over 1,000 players were considered — by baseball experts — to have more ability and potential than Buehrle. And yet here he is, a decade later, one of the most accomplished players of this generation.

What happened between the draft and today? Why did he make it big, and so many of the players drafted ahead of him did not make it at all? What is the nature of ability?

Dr. Carl McGown, renowned volleyball coach who helped shape the Olympic gold medal-winning men’s program, always says, “Initial ability and final ability are not closely correlated.”

What does that mean? It means that the athlete that you see today tells you very little about what that athlete will look like years from now.

Let’s say you’re a high school coach, and you’re welcoming the freshman class for the first day of tryouts. What do you see? Certain players will seem to have something we are tempted to call “talent.” They pick things up right away, seemingly without effort. And after this initial impression, a variety of things can happen.

In one scenario, the athlete can continue to grow and to improve, and thus become a star. Or the athlete can quickly level off, never improve, and become what we might call a disappointment. Or the athlete can fall somewhere in between those extremes.

Meanwhile, there’s another athlete standing in front of you. This one doesn’t impress on the first day of practice. There is no sign of “talent.” Yet this athlete keeps showing up for practice, and suddenly you find yourself saying, “Hey, this kid has really improved.”

The question, of course, is why does one player keep improving, while another does not?

That answer is for another post. For now, what’s important to remember, with fall tryouts just around the corner, is not to jump to conclusions about the athletes in front of you. When you’re faced with a close choice between keeping a player and cutting players, keep as many as you can! You never know which one will become a star. Initial ability and final ability are not closely correlated. That’s not just something that professors say. Mark Buehrle is living proof.