Looking at Greinke’s Fastball

Despite not being named to the All-Star team, Zack Greinke is still having another successful season. His FIP stands at 3.49, his xFIP at 3.69, and his tERA at 3.45. However, while those numbers are certainly impressive, they are nowhere near his insane 2009 season, where his 2.33 FIP netted him 9.4 WAR and his 2.58 tERA brought his ERA to 2.16.

Amazingly, Greinke probably knows all this stuff as well. From The New York Times last year:

To that end, Bannister introduced Greinke to FIP, or Fielding Independent Pitching, the statistic Greinke named Tuesday as his favorite. It is a formula that measures how well a pitcher performed, regardless of his fielders. According to fangraphs.com, Greinke had the best FIP in the majors.

“That’s pretty much how I pitch, to try to keep my FIP as low as possible,” Greinke said.

Because he’s such a smart pitcher, I wanted to see if Greinke has made any adjustments from last season, specifically to his fastball. Despite being only 26, Zack has lost some life on his fastball over the past few years. Here are his average four-seam and two-seam fastball velocities since 2007:

2007: 94.4, N/A
2008: 93.4, 90.4
2009: 93.7, 89.1
2010: 92.9, 93.1

Something weird is going on here. His two-seam fastball jumped 4 MPH this year and is somehow now faster than his four-seamer? This looks to be a classification error, as BAM has had issues with their two-seam classification in the past. Our own Dave Allen also says that Greinke’s two-seamer is usually close to the velocity of his four-seamer (now that’s a nasty weapon). Pitchf/x guru Harry Pavlidis did say however that, “A little more tail on the four-seam fastball, too. Seems like 2007’s version lacked some of the downward tilt he’s had more recently.” His wFB was -3.8 in 2008, but had a monstrous 2009 at 25.8 and is on track for a very good, but not 09-esque, 2010. However, Greinke is also getting more ground balls, meaning he could be trying to fine-tune his game even moreso. Here are his career groundball rates:

2004: 34.6%
2005: 39.2%
2006: 35.0%
2007: 32.1%
2008: 42.7%
2009: 40.0%
2010: 44.0%

This year Greinke has the highest groundball rate of his career, the lowest line-drive rate, and the second-highest GB/FB ratio. However, he’s also striking out about two batters fewer per nine innings, so he may be giving up some speed and power for more balls hit on the floor. We can take a closer look at Greinke’s fastball (all types) location, as shown by data in the Bloomberg Sports Pro Tool. Here’s 2009:

For proper analysis, make sure to notice where the outlined batter’s box is in relation to home plate (the top/bottom/far left/far right portions inside the white lines of the batter’s box are a few inches out of the strike zone). Greinke threw his fastball on the outside corner to lefties/inside corner to righties. However, he threw the ball vertically similar to how he did in 2008, staying about belt-high. Here’s 2010:

Here we see a significant difference. Greinke is throwing his fastballs lower in the zone and more out over the plate. It could be that he’s throwing his two-seamer lower, or at least enough to make a difference. For a relative comparison, here’s where his four-seamers are for 2010:

As you can see, Greinke’s four-seamer is well higher in the zone than his overall fastball average, and another image of his two-seamers that I won’t show in order to avoid overkill does indeed show he’s throwing it very low in the zone. While this may not be the definite reason for his career-high groundball rate, I’d like to think that it’s a front runner. Whatever he’s doing, it’s working. Greinke has put together another excellent season thus far.