How baseball players catch fly balls has been a mystery for years. Has this mystery been solved by a theory? Scientists might have cracked this case wide open. Professional baseball players for example, "Adjust their speed to arrive at the landing spot, just before the ball arrives." According to Dan Peterson, the author, they do this to ensure a catch. I always thought catching fly balls was easy and I'm sad to say it's not as easy as it looks. I may be mistaken but the scientists aren't. They made players do a field test to see if it's easier to sprint once or move freely. The players had better results when they were allowed to move freely. The term scientists use is "Optical Acceleration Cancellation." How they catch the ball with the sun in their eyes, is a different story, but we can look at that another day.
Source:
http://www.livescience.com/culture/090403-sports-baseball-catch.html