Every fantasy baseball owner has felt the temptation to pick up that waiver wire player who is hitting .400 early in the season with the hope that he's figured something out and will take the league by storm. Modern research, however, has taught us not to trust such small samples and to expect that a hitter's batting average on balls in play (BABIP) will tend to stabilize near the league average over the long haul, when factors like opposing pitchers and defenses presumably even out.
There are, however, two primary ways to beat this theory, even over the long haul: hard contact and speed.
The better hitters tend to hit the ball harder and on a line more often. These batted balls are more difficult to field and go for hits more often. Using Baseball Info Solutions' hit location and batted ball timer data, we can approximate the number of hits we could have expected given the characteristics of each hitter's balls in play.
For example, let's look at ground balls. Miguel Cabrera hit the hardest groundballs in 2011, averaging 57.8 mph through the infield compared to the major league average of 50.6 mph. Based on the velocities and trajectories of his 215 ground balls, we would have expected him to get about 59 hits on grounders (a .274 average, compared to the league average of .231), which is exactly how many he had. Of course, Cabrera does the most damage on line drives and deep fly balls, but getting hits on ground balls helped him maintain a lofty batting average and win the American League batting title.
Extending this analysis to all balls in play, we find certain hitters get more out of their balls in play. Hitters like Adrian Gonzalez, David Freese and Joe Mauer put the ball in play with authority and it leads to extra hits and a higher batting average.