There's a school of thought that pitchers primarily control strikeouts, walks and fly balls allowed, but don't much control what happens once the ball is put into play, i.e., whether a batted ball finds a fielder or an empty space. Sure there are exceptions like knuckleballers who typically induce weaker contact, but for the most part - the theory goes - batting average on balls in play allowed is largely random for pitchers. As a result, it's should be a safe bet that pitchers like Felipe Paulino (.341 BABIP in 2011) , Ricky Nolasco (.331) and Edwin Jackson (.330) should all normalize toward the league average (.295) in 2012 - or at least their teams' average, assuming their defense is roughly equal to last year's. (The Marlins, for example had a team BABIP allowed of .297). But is it?

Assuming non-knuckleballers don't have a lot of say in their BABIP, the pitchers with the best and worst career BABIPs should be roughly equal, with the best BABIP's having a slight advantage simply due to their good luck on balls in play. But over an entire career, that luck (a) shouldn't be too extreme because the sample is so large, and (b) fluctuates so much over time.

There are 176 pitchers who have thrown at least 1000 IP since 1995. Let's take a look at the best-50 and worst-50 by BABIP:

As you can see, there's arguably only one (marginal) Hall of Famer (Andy Pettitte) among the bottom 50, and one current star (Zack Greinke). Among the top 50 are the following: Mariano Rivera, Matt Cain, Johan Santana, Jered Weaver, Tim Hudson, Pedro Martinez, Cole Hamels, Tom Glavine, Greg Maddux, Justin Verlander, Kevin Brown, Brandon Webb and Jake Peavy.

Maybe I'm underestimating how much BABIP "luck" spares pitcher arms, giving them better health and more confidence, but even so, that would be reason enough to take it seriously, even if it were pure luck initially. More likely, though, while BABIP - like batting average- fluctuates greatly week to week and even year to year, for the most part it's a greatly associated with more skillful pitchers.

That's not the same as saying Nolasco, Paulino or Jackson can't bounce back - or can't as Pettitte and Greinke (so far) have overcome bad luck/inability to induce weak contact - or that |STAR|some|STAR| of BABIP can be explained by luck. Just that a poor BABIP very likely has a repeatable skills component to it and that you should be wary targeting outliers for bounce-backs without some other compelling reason.