There are few aspects of life where you can fail seven out of 10 times and still be considered great at what you do. With a 30 percent score on the MCAT, you wouldn’t get into medical school. You’d likely lose money if you only won 30 percent of your Super Bowl bets. But in baseball, if you get a hit 30 percent of the time you step up to the plate, you might be headed to the Hall of Fame—and that’s because it’s perhaps the most difficult thing to do in any major sport.