Just HOW Perfect Does Practice Make?

Recently Vox ran an article titled “I was really bad at sports in high school. This new study helps me understand why.” The author, Brian Resnick, then goes on to cite a meta-analysis that looks at 33 studies, to explain the marginal effect of practice on athletic achievement. That’s a pretty astounding proclamation, that “practice doesn’t explain why the best athletes are so good,” as the article states.

So how did the meta-analysis reach the conclusion that practice only accounts for 18% of success? Well, let’s take a look at some of the potentially limiting factors of this type of study:

  • Self-reported results. When athletes report their own practice times, that data may not be 100% reliable
  • Other variables that account for performance. The authors of the meta-analysis were unable to account for other factors that may correlate with practice, such as the fact that less naturally gifted people may practice more to compensate, or possibly even less because they just play a sport on the side. Remember – correlation does not necessarily equal causation.
  • Differences among sports. Depending on the sport, practice may play a larger (or smaller) role. For example, genetics may have a significant impact on a sprinter’s natural speed, but only a small impact on a pitcher’s curveball accuracy

Finally, consider where the 18% figure came from. From what we see, it belongs to a pie chart titled “overall.” But when you look at the chart titled “Mixed” (denoting a mix between sub-elite and elite samples), it jumps to a much higher 29%, implying that the difference between elite and sub-elite athletes is much more attributable to practice.

So, does practice make perfect? It’s hard to say. But if you want to be an all-star data expert, it certainly helps to take a closer look at the numbers.