Joel Hanrahan: Different, but the same?

Over the past week or so, the Pirates have cooled off. They now stand five-and-a-half games back in the NL Central after being right at the top for much of July. However, they’re still in the race, and surely they’re exceeding almost everybody’s expectations.

Today, let’so focus on the Pirates’ All-Star closer, Joel Hanrahan, who is having an exceptional year out of the Bucs’ pen.

Hanrahan came to Pittsburgh in 2009 from Washington in exchange for Nyjer Morgan. He had his breakout season in 2010, throwing nearly 70 innings with a strikeouts-per-nine rate of just under 13. In his first season as closer, he’s been much better at preventing runs, with an ERA two-and-a-half runs lower than it was last year, but the underlying peripherals are pretty similar:

BABIP is the batting average on all contacted balls excluding home runs; HR/BIA is the home rate on all balls in the air (fly balls, line drives, pop ups).

Are you seeing what I’m seeing? (You don’t actually need to answer.) The ERA has had quite a swing, presumably due in most part to random variation on ball-in-play outcomes. The FIP is down due to (probably unsustainable) home run prevention, but xFIP, which regresses home run rate to the league average, sees the same pitcher both years. So, keeping this in mind, let’s dig slightly deeper.

That table tells something of a different story. Though the cumulative walks, strikeouts, and groundballs are similar from year to year (evidenced by the similar xFIPs), Hanrahan is piecing them together differently this year. He’s gone from a strikeout-heavy, walk-prone, slight flyball pitcher to a groundball/control artist with strikeout and whiff rates still above average.

So now you may be thinking, what’s causing this? To answer this question, it’s best to look at the PITCH-f/x data we have on Hanrahan from 2010 and 2011.

Hanrahan’s a two-pitch guy, showing a high-90s fastball and a mid-80s slider. If you look at some individual pitch metrics, you’ll see that things are pretty much the same:

FASTBALL

SLIDER

The fastball finds the zone more, and it’s gotten more whiffs and grounders this year. The slider has been thrown for a ball more, but also has generated much less contact in a limited sample. Basically, the fastball looks similar to its 2010 form, and the slider actually looks like it might be a BETTER strikeout pitch than it was last year.

So, what’s the difference in Hanrahan’s approach that’s causing him to pitch more like a, for the lack of a better term, finesse pitcher? As you may have guessed, it has to do mostly with how Hanrahan has mixed his two pitches.

The columns below show Hanrahan’s pitch mix in each ball-strike permutation. Especially to lefties, he’s drastically cut his slider usage.

So it looks like that’s all there is to Hanrahan’s new approach. He hasn’t added anything to his repertoire, and his bread-and-butter fastball gets the same results. But by turning to the fastball 83% of the time overall, he’s been able to throw strikes much more consistently.