Antonio Bastardo‘s emergence has been just one highlight among many for the 2011 Phillies. Out of a group that has endured plenty of injuries and ineffectiveness, Bastardo, along with Michael Stutes, has been one half of a young, cost-controlled duo that serves as a sturdy bulwark for the Phillies in the late innings. With Ryan Madson returning from injury in mid-July, the ability to call on Bastardo’s reliable out-getting whenever the situation demands gives Charlie Manuel an extra queen on the chessboard. With 44 and 2/3rds innings pitched, Bastardo currently boasts a 1.41 ERA. And it’s far from smoke and mirrors — he’s shown an elite ability to miss bats, posting a 30.7% strikeout rate, good for 12th among qualified MLB relievers. It would be easy (and not entirely wrong) to point to his .156 BABIP and crow about another unsustainable reliever season built on batted ball fortune. But SIERA, for its part, likes him to the tune of 2.57, and there are a few quirks to his underlying numbers that merit a closer look.
You would expect a southpaw with good velocity and a high strikeout rate to be particularly nightmarish for left-handed hitters. Broadcast crews, though, are fond of pointing out that lefties opposing Bastardo hit for a higher average than righties. The more comprehensive wOBA metric agrees — left-handed batters are 64 points better, .240 to .176 (it’s worth taking a moment to stop and appreciate just how good both of those figures are). This is particularly unexpected when considering Bastardo’s approach. The changeup would be a good weapon against righties, but, in Bastardo’s case, it’s the weakest pitch in his arsenal. So he boosts his reliance on his greatest asset, the fastball, when facing righties, opting for it about 66% of the time, as opposed to 60% against lefties. He doesn’t dial down his selection of the slider as much as you might think, but his location of it differs substantially:
With the slider breaking in on right-handed batters, Bastardo is likely trying to avoid plunking them. The result is that a good deal more of them are left in what could be called the middle of the plate, or at least in areas where they appear a lot more hittable. There’s some indication that they are — lefties have yet to manage a line drive off of Bastardo’s slider, while righties have done it 11% of the time. Yet righties still whiff prodigiously against it (41.8%) and ground out quite a bit on it (33.3%) which, considering the juicier locations, must in part speak to its substantial “bite.” In terms of outcomes, it hasn’t mattered. Righties haven’t managed any substantial power off of Bastardo, posting just a .064 ISO and managing only four extra-base hits in 108 plate appearances. This could be an area where lady luck is especially forgiving, though. None of the line drives or flyballs hit on Bastardo’s slider have fallen for hits thus far. His overall BABIP against right-handed hitters is just .141. As that creeps back up, all three pitch types to righties will find different areas of the park, and likely the outfield seats as well. Since his BABIP against lefties stands at .200, it’s reasonable to expect his odd platoon split to reverse itself.
Here’s one thing that will always help your BABIP: Bastardo has been an inveterate inducer of the infield fly this season. Currently, almost 20% of his flyballs stay in the infield, good for 7th among qualified MLB relievers. Pop-ups are outs all but some negligible percentage of the time (the Luis Castillo caveat), so, in combination with his strikeout rate, the infield flies allow Bastardo to have more success with such a low groundball rate than he otherwise might. There’s plenty of varying opinions on how much of a repeatable skill the induction of infield flies actually is. Last year, David Appelman of Fangraphs offered some evidence that higher infield fly rates are just a natural byproduct for pitchers with higher overall flyball rates, a category which Bastardo certainly fits.
This year, Derek Carty at Baseball Prospectus searched for thresholds at which we could consider various statistics to be “stable,” and included a pitcher’s infield fly rate in his endeavors. He found that it stabilizes once the pitcher has amassed a combination of groundballs, flyballs, and line drives totaling 288. Bastardo stands at 97. So while the infield fly rate is encouraging, it’s far from a sure thing just yet. Don’t underrate its importance. If Bastardo can maintain it at around 15% or above, he can keep his HR/FB% down and mitigate the damage of his high overall flyball rate.
No matter how you slice it, Bastardo is due for some backsliding in metrics that no pitcher can really control. In cases such as his, though, we can step away from the batted ball data and pitch f/x and reach into our old reliable peripherals toolbox. Bastardo has an elite strikeout rate and a slightly below average walk rate. In most cases, that will give you a solid foundation for effectiveness as a reliever. In his case, any ERA retrodictor you might care to ask — FIP, xFIP, SIERA — likes what he has to offer, to varying degrees. His highest, the 3.31 xFIP, doesn’t account for some of the above mentioned factors that could keep his home run rate down. But even if he settles down around that figure, that’s more than enough to make him a valuable high leverage asset for the Phillies, and, should Ryan Madson depart for top dollar this offseason, the cornerstone of a new bullpen.