Batting average on balls in play (also known as "BABIP" or "hit rate") is exactly what it sounds like—the proportion of batted balls hit within the confines of the baseball diamond that fall for hits. The league average is always right around .300.
BABIP takes years to stabilize and become reliable because it is particularly prone to being affected by random chance. Some players—powerful line-drive hitters and speedy ground-ball hitters, for example—have the ability to maintain hit rates significantly higher than the mean, but most big, year-to-year fluctuations are just luck.
Thanks to The Hardball Times' Simple xBABIP Calculator, we can get an idea of what a player's hit rate would be in a luck-neutral environment based on factors like power, speed and batted-ball profile.
In order to calculate the context-neutral stats for the players on this list, I substituted their xBABIPs for their BABIPs to find their adjusted batting averages. I then used their walk rates to find their expected on-base percentages and applied their Power Factors to calculate expect slugging percentages.
Finally, I calculated each player's expected OPS+ to compare with his actual OPS+. It's an imperfect method for comparing offensive production, but it at least gets you in the right ballpark.
If you don't believe that this system has any predictive power, ask Austin Jackson.