It's widely believed that for pitchers, batting average on balls in play is largely due to luck and that over time, will settle toward .300. Put differently, 30 percent of batted balls that don't go over the fence are expected to drop in for hits regardless of the pitcher. (This does not account for extremely good or bad defense, but assuming the defense is close to average, the main explanation for severe deviations from a .300 BABIP is dumb luck).

But as I've noted before, some pitchers seem to defy that logic - Carlos Zambrano in particular routinely allows considerably less than a .300 average on balls put into play against him. (This year, it's .285, the sixth in a row that it's .285 or less). One explanation for Zambrano's uncanny ability to prevent batted balls from becoming hits could be his excellent stuff which has velocity and movement. But there are plenty of pitchers with excellent stuff (Tim Lincecum, Dan Haren, Justin Verlander) who don't show any sustained skill at preventing batted balls from becoming hits. Meanwhile knuckleballers (Tim Wakefield in particular) also seem to post consistent sub-.300 BABIP readings. So instead of looking at Zambrano's stuff, maybe it's more important to focus on what he has in common with Wakefield - notoriously poor control.

While Wakefield's BB/9 aren't nearly as bad as Zambrano's over the years, a knuckleballer really has no idea where his pitches are going, i.e., he has little control in the literal sense. Zambrano has lead the league in walks twice. But perhaps that also makes it harder for the hitter to know where his pitches are going, and therefore harder to hit with authority. Zambrano is eighth lowest among pitchers since 2002 in line-drive percentage allowed. (Wakefield is second, and the other six pitchers are either extreme ground ballers (Brandon Webb, Derek Lowe, Tim Hudson) or control challenged (Jason Marquis, Jose Contreras, A.J. Burnett).

So it might well be that there's an inverse relationship between control and BABIP. If your control is excellent, you don't throw a lot of balls, and therefore you run the higher risk of having them struck with authority and drop in for hits. Now, if you paint the corners perfectly and have late movement within the zone, maybe you can have it both ways, but keep in mind even Pedro Martinez had a .343 BABIP in 1999, and he had a 313/37 K/BB ratio that year.

The point isn't that you should draft pitchers with poor control because the BABIP gains are likely to offset it - in fact, BABIP fluctuates a lot due to luck, and you're better off putting your faith in someone who does not depend on luck to keep hitters off the bathpaths. But it's worth noting that BABIP isn't a holy grail stat, and for the two steps forward a pitcher gains in control, it's possible some take a step back in terms of being more hittable. We see the reverse happen with hitters whose BABIP and power often decline when they make a conscious decision to improve their plate discipline.

I suspect the balance differs for each hitter or pitcher, but more control and more plate discipline is not always better. Some pitchers are better off throwing more out of the strike zone pitches, and some hitters are better off hacking.