Zack Greinke is confusing. Two years ago he put up the kind of jaw-dropping numbers that come along only about once a decade. Last season he was still pretty good, but there wasn’t anything about him to make you sit up and take notice. He’s going to be on the market this winter and teams looking to trade for him are going to wonder which pitcher they’re getting.
Let’s dispense with the formalities quickly. All the underlying numbers agree that Greinke was not as good in 2010 as he was in 2009. I’ve never been a fan of looking at changes from just one season to the next, though. I believe looking at a player’s entire career can show trends and abilities that might be missed looking at only one or two seasons of data. Looking at ERA, FIP and xFIP over his career, we see mostly the same things. ERA varies the most (as it will), but they pretty much all agree that 2009 looks like Greinke’s career year.
That wouldn’t be so surprising. Plenty of pitchers peak early, but Greinke has always looked so promising, and no one wants to give up hope. Justin at True. Blue. Meh. did some interesting work on this in June. He wonders if there’s a mechanical issue with the curve, which was posting a much lower value and breaking less than in 2009. There was reason to hope, though. He points out that Greinke was giving up more homers than normal (this normalized as the season played out) and leaving fewer runners on base (this did not).
When we look deeper, it gets bleaker.
Looking at PITCHf/x from the last two years, he doesn’t look like the same pitcher at all. He’s suddenly throwing a two-seamer almost 30 percent of the time, his changeup use has more than doubled (up to 12.2 percent now) and his fastball, slider and curve are all being used less.
Why has Greinke made these changes? I don’t know, but if we look at a longer trail of data, it starts to look like he’s compensating for diminished abilities. His velocity seems consistent, a good sign, but frankly, his curveball and slider just don’t move like they used to. And this isn’t a one-year aberration. The movement of these two pitches, especially the curveball, has been declining for years now. Four years ago, his curveball was breaking 8.1 inches horizontally, now it’s down to 4.5. His slider had a 5.7 inch horizontal break, but now it’s only 2.9, and the decline has been steady for both pitches.
What’s more, the values on all of his pitches (except his changeup which went from bad to somewhat less bad) have really fallen compared to 2009. The worst part is that, except for his troublesome curveball, the 2010 values really aren’t out of line with his career numbers.
This is a sad story, but it’s hard to deny. I keep looking at the numbers, trying to find something that will tell me that Greinke is poised to bounce back. I do think he’ll post somewhat better numbers next year due to a better strand rate, but I don’t think he’s going to blow our minds again.
I hear sometimes about the belief that Greinke can turn it on whenever he wants. Maybe he can, I don’t know. What I do know is that, looking at the numbers, looking at what his pitches do, it’s hard not to see someone whose skill set is changing from that of a fantastic pitcher to that of one who is “only” very good. I think that’s what you can count on next year. He certainly isn’t going to hurt a team, but he’s not going to dominate like the 2009 Greinke.