High and Tight: Zack Greinke’s Missing Curves

Since he’s become a regular starter, it’s tempting to look at Zack Greinke‘s career and say that he’s been about the same pitcher with an outstanding peak in 2009. Other than that wonderful year, he’s managed an FIP in the mid-threes by striking batters out at a slightly-above-average rate for a starter and showing excellent control of his four-pitch mix. He’s no metronome – his ground ball to fly ball mix has oscillated – but he seems pretty stable.

But zoom in on just the last two years, and the change seems startling. He went from striking out 9.5 batters per nine to a mere 7.4. He added a run of FIP. His swinging strike percentage dove two percent (from above to below average). And his ground-ball rate changed, as is his wont (from dead-on average (40%) to above-average (46%)). His pitching mix changed fairly significantly, too, dropping almost four percent of his curves and five percent of his sliders, while almost doubling his changeup usage.

And yet, with these changes in his mix, many aspects of his repertoire stayed the same. Looking at his Pitch Type Values, he still had an excellent fastball (10.1 runs above average, +39.8 over four years) and slider (12.3 runs above average, +49 over four years). His changeup was still meh (2.5 runs below average, -13 over four years). Since these numbers include luck and only measure actual results measured by linear weights, we do want to treat these numbers with a grain of salt, but sustained numbers in either direction seem to suggest that his fastball and slider are strong pitches.

So what happened to his curve last year? With the above caveat in mind, his curve went from a scratch-or-better pitch to below average in four years, like this: 2007: +1.5; 2008: +0.5; 2009: +2.4; 2010: -7.0. That last number could have been due to luck – a few curves might have been smacked past a diving infielder, or dunked into short center – but could there have been more going on? The velocity didn’t change much, and though the curve had less movement, there’s been some variation on all of his pitches over the course of his career.

Let’s check the heat maps. It’s why we have these toys. Take particular notice of the top quarter of the strike zone in the maps below.

It certainly looks like he threw fewer high curves to righties in 2010, doesn’t it? If you check back further, you see that those same high curves to righties were ‘missing’ in 2008, too. Now, curves have good whiff percentages when compared to fastballs, but we can’t blame all of his missing strikeouts on his reluctance to throw the high curve. And this still could just be the normal variation that a pitcher goes through as he adjusts to the league and the league adjusts back.

Looking back at Dave Allen’s excellent piece on Tommy Hunter‘s high curves, we find this prescient line, given the fact that Greinke got fewer strikes and more grounders when he used the high curve less in 2010:

It is an interesting pitch: while the average curve gets lots of called strikes and grounders, Hunter’s gets many more swings and then flyballs.

I’m no pitch f/x guru, but I know some. Lucas Apostoleris, from Beyond the Box Score and Don’t Bring In the Lefty, has worked up Greinke’s 2010 pitch f/x data before and was kind enough to run the numbers. It turns out that yes, with the caveat that Greinke has as many as three different kinds of curve balls, his “curve” did get more swings in 2009 when it was higher (41.3% swings in 2009 vs. 34.6% in 2010). Alas for our comparison to Tommy Hunter’s high curves, Greinke got fewer fly balls on the pitch in 2009 (29.5% in 2009, 39.7% in 2010) while his groundball rate remained virtually unchanged. Instead, his curve got more whiffs when he threw the high curve (28.2% whiffs in 2009, 19.9% in 2010). Not quite the same thing that happens with Hunter’s high curves.

And before we get all caught up in the lack of the high curve, there is indeed some luck at play. Josh Smolow, Garik16 at Beyond the Box Score and twitter, said:

His curve by my database has a run value of +4.0077 (positive = bad). But if you use expected run values, which are not BABIP or results dependent, the Curve is NEGATIVE 3.7156, a difference of over 7.

So what we have here is a minor change in Greinke’s curveball philosophy followed by some poor luck with the new approach. Given that the swing and whiff rates were higher when he threw the higher curve, it wouldn’t be terrible for him to return to his 2009 approach. That won’t mean he’ll win another Cy Young, but we shouldn’t discount the possibility that throwing some high curves to righties this season will serve Greinke well.

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Graphs: Baseball, Roto, Beer, brats (OK, no graphs for that...yet), repeat. Follow him on Twitter @enosarris.

34 Responses to “High and Tight: Zack Greinke’s Missing Curves”

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  1. DonM says:

    He pitched to a different catcher last year. Could that have contributed to the resultss?

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  2. Telo says:

    It’s Greinke’s customary behavior to raise his GB rate from 40% to 46%?

    I ain’t no english major, but I don’t quite get the usage of wont there.

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  3. BrettFan1 says:

    One variable to keep in mind here is that Greinke stated in the offseason that he decreased his usage of his slider to protect his arm late in the year. He indicated that he didn’t want to hurt his arm throwing the slider when the year was already a lost season for the Royals. He could have also decreased his use of the curve and just not mentioned it. One of the biggest things I noticed about the 2009 performance versus ’08 and ’10 was the impact of the catcher. Olivo was a horrible catcher in general, but he did have one attribute that seemed to positively affect Zack, aggression. Zack seemed much more aggressive in his pitching style and more likely to go for the punch-out when he had two strikes when Olivo was catching.

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    • tbr says:

      I beg to differ. Greinke threw fewer sliders in 2010, yes, but he never gave a reason, much less one that indicated he was trying to protect his arm. That was pure speculation by people trying to put a reason on his reduced slider usage.

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    • Bob says:

      Or, Greinke’s infrequent use of sliders may have led him to throw more curveballs in situations where he would normally throw a slider, giving hitters something better to look at.

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  4. Telo says:

    As Tango preaches, regressing carries over to pitch f/x work as well. Everything here, even though it seems very granular with large samples of data, needs to be regressed. You definitely didn’t ignore that – you mention the LWTS on his CU should be taken with a grain of salt, but the idea that high curves in general get more whiffs than low curves is something I would have to see lots more data to believe – much more than Dave Allens’ piece and Grienke’s two year semi-trend.

    Are pitchers ever trying to throw a high curveball? I can see that Hunter certainly does, but that is clearly the exception rather than the rule.

    I’m having trouble grasping anything here that is significant – but I’ve just started digging in. Give me a few.

    The bottom line is – I don’t have nearly enough here to believe that high curves are better than low curves, and that kind of undercuts the whole article.

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    • Eno Sarris says:

      The problem here might be that I’m way better at asking questions than answering them.

      I’m not suggesting that this is a trend across baseball, really, but it’s an interesting question. Also, I do think people aim their curves. While researching this article, I was told that Greinke even referenced dropping the high curves in an interview, but I couldn’t find it.

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      • Telo says:


        Someone has to ask the questions, right?

        There is definitely something to this, too. I was really trying to play devils’ advocate from the math perspective. Here’s my thought process, from a no-numbers/pure baseball perspective:

        Let’s assume for a second that high curves really DO get more whiffs and better results:

        Very seldom does anyone ever try to throw a high curve ball, even less often than a pitcher will try to throw a back door breaking ball. They are dangerous because, obviously, they break into the middle of the zone. Of all of the CU thrown high in the zone, probably >80% are mistakes (of atleast 6in) (and again, Hunter is an interesting exception).

        However, because hitters rarely look for these pitches, they are often effective. If a batter picks up a very high trajectory, he’s first move is to let it go, but when he sees it breaking over the plate his could be tempted to put a bad/late swing on it, resulting in whiffs.

        So, there is some game theory going here. Like bluffing in poker, there is correct number of high curves to throw where the batter will still be surprised by it, and thus put a bad swing on it. Throw high curves any less than that, and you aren’t taking enough advantage of the pitch; throw it any more and the batter will show better results – he’ll know it’s coming, and it’s really not that hard of a pitch to hit, it’s only good because it’s a surprise.

        So, in the end, it’s fundamental pitching to keep your Curveball low in (and often out of) the zone, and Grienke showing the ability to do so seems like a plus to me. However, if there was real data that showed these high curves DO get better results… well then, fundamental pitching should change to abide the game theory above – and you should throw the high curve just enough that batters don’t start to look for it.

        Still… in the end…. the real point is, you have to have a pretty solid deuce to be able to sit on the mound and throw the sucker so it breaks right into the upper half. Which is kind the base of my friction with the whole idea. But at the same time, Grienke is just the kind of crazy (and crazy good) pitcher to fearlessly throw it. Like the time he “called his pitch” in the dugout before the inning and threw a 50 MPH curve the next inning.

        Oh, Grienke.

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      • Telo says:

        Short version, I don’t buy the theory that you, the average pitcher (or pitcher with an average CU) should be trying to throw high curves, except when you have supreme command of it, and are confident you won’t leave a flat meatball in the go-zone for the batter.

        That being said, Greinke is just the kind of guy who should probably mix in a few high deuces.

        That’s a lot of writing to end up saying “I agree. He could probably benefit from a couple more high curves next year.”

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  5. Pat says:

    His wife isn’t missing any curves, that’s for sure…

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  6. DL80 says:

    “an FIP”? Wait, what? Am I the only person that always reads it in my head as “fip”? Do most people say it out, as in “F-I-P” like “E-R-A”?

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  7. phoenix2042 says:

    how do you pronounce wOBA? I say “woah-ba” in my head, even though it sounds really weird. i usually say F-I-P though.

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  8. Eno,

    Greinke intentionally changed his pitch usage last year to protect his arm for later use on a team that had a chance to win baseball games


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    • Eno Sarris says:

      there’s the link! It mostly focuses on slider, but an interesting thing to be so candid about.

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      • puffy says:

        “but an interesting thing to be so candid about.”

        He’s an intelligent guy. Smart people don’t insult people’s intelligence by denying the obvious.

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  9. kds says:

    wOBA was developed and named by Tango. He has said very specifically that he chose the name based on a Sesame Street song. FIP is like taking the rude finger out of “flip off.” xFIP is is a little more polite, due to the normalization of HR/FB%. BABIP, (repeat quickly several times), should sound like a truck backing up. Here we have eff wore, (fWAR), at other sites they use arrr warrrr, (rWAR). The replacement level for WARP is too low, violating special relativity. VORP, as all your mothers told you, is a rude sound, never appropriate for the dinner table, even if it will make your little sister laugh. Pythag uses squares not triangles, so you have to rotate pi/4 to get a baseball diamond. I better quit before I get to a late inning pressure situation and need to depress my clutch, or my get up won’t go. And you want me to get up and go; digitally speaking.

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  10. camisadelgolf says:

    You misspelled ‘Zack’ on the first line.

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  11. Steve says:

    His curve has gone the way of Lincecum’s; it’s just spins to the plate and doesn’t have a hard break. I never really thought much of Greinke’s curve. I thought it was played up due to his overall reputation as being a master craftsman of all pitches, a 5-6 pitch guy. To me, his regular speed curve in the mid-70s and super slow one in the mid-60s were never effective. I’ve seen a lot of homers off his curve. His slider is devastating however. As much as he was thought to be a touch and feel, cerebral pitcher, he’s become the classic power fb/slider pitcher, with just an average change and below-average curve to finish things out. He’s more John Smoltz than Greg Maddux.

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  12. I love how so many people post uninformed comments! First Zach did say that he intentionally stopped throwing his Slider to save his arm for the next season. Grienke is the type of person that needs motivation to pitch. It’s obvious with his low key demeanor and weird wit that he he doesn’t understand just how talented he is. Look real close at his 2009 #’s and you’ll see that not many Pitchers in the history of the game has put together a whole season like the one he did. The man could have won 25 games if he were on a better team. He lost countless games and had allot of no decisions in games he gave up 0 to 2 runs.And if anybody doesn’t know, he throws a really good Curve!!! He throws 3 different ones and has command of all 3, so all this talk that he has a below average Curve is nonsense! He has uncommon command of all of his pitches and he’ll be motivated this year and Zach will dominate the NL and win his 2nd Cy Young. His ERA will be less than 2 and everyone is going to eat they’re words because they talk w/out knowing. He developed into one of the most talented pitchers to ever grace the mound, the reason he doesn’t have the #’s to prove it is because even he doesn’t know how talented he is. When he figures that out the rest of the league is in trouble because they also have to deal with Gallardo and Marcum as well. World Series our Bust!!

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