Looking at A.J. Burnett’s whiff rates by pitch

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2011 Draft: Opening Thoughts
(AP Photo/Charlie Neibergall)

During yesterday’s podcast, Joe and I talked very briefly about A.J. Burnett and the swing-at and swing-and-miss rates of his various pitches over the last few years, but I think it’s something worth looking at a little more. After all, his ability to rebound from a subpar 2010 campaign is unquestionably one of the biggest stories of the upcoming season.

Burnett is primarily a two-pitch pitcher, throwing mostly fastballs and curveballs, though he’ll occasionally break out a change from time to time. You’ve got to have pretty good stuff to survive ten-plus seasons in the big leagues with two pitches, which A.J. certainly does. Whether or not that stuff is declining due to age or his Low Pitching IQ™ is another matter all together. I looked at the last three years worth of data, so it’s his last season in Toronto and first two seasons in New York. Let’s start with the ol’ number one…


Burnett actually throws kinds of fastballs, but the PitchFX system has trouble distinguishing between his two- and four-seamers. I’ve lumped them all together in one uber-fastball category, which isn’t completely accurate but works well enough for our purposes. He’s consistently thrown the heat two out of every three pitches over the last three years, though he was a bit over that last year, seven out of every ten pitches.

Hitters have swung at Burnett’s fastball(s) about 45% of the team over the last three seasons, pretty consistently as well. A percentage point one way or the other is nothing. His whiff rates have varied wildly though, falling close to three-and-a-half percentage points from 2008 to 2009 before climbed back up a percent-and-a-half last year. It’s worth noting that A.J.’s velocity is gradually declining, which isn’t terribly surprising as he enters his mid-30’s. Still though, he averaged 93.1 mph with the heat last year (down from 94.2 in 2009 and 94.4 in 2008), plenty enough to survive in the big leagues.


The hook has been Burnett’s bread-and-butter over the last few years, a pitch that has checked in at 38.9 runs above average since 2007. Only three pitchers own a better yakker during that time: Adam Wainwright, Wandy Rodriguez, and Roy Halladay. Hitters still swung and missed at the pitch with great frequency in 2010, though the whiff rate was down almost three percent from the year before. Overall, Burnett threw the pitch less often, but hitters swung at it more often and made more contact.

It shouldn’t be a surprise that A.J. uses the pitch primarily when ahead in the count, especially with two strikes. If a batter was down 0-2 or 1-2, there was a ~60% chance that they were getting the hook. The lack of whiffs (relatively speaking, of course) helps explain why Burnett had trouble putting batters away at times in 2010, something that really shouldn’t happen with stuff that good.


It’s not often that Burnett breaks out his changeup, but we’ve definitely seem him do it on occasional. He’s thrown basically two or three or four changeups per start over the last three years, so the whiff data isn’t terribly reliable. It’s just a really small sample size. If he throws three per start, gets the batters to swing at it about 39% of the time, and the batters miss about 7% of the time, that means he’s getting one swing-and-miss on a changeup for every like, ten starts. The pitch just isn’t a core piece of his repertoire, and he’s tried to incorporate it more over the last few years, but at this point it’s safe to say it’ll never be a go-to pitch for A.J.

* * *

So What Does It Mean?

Damned if I know. I just thought it was interesting that Burnett’s whiff rates for the fastball have fluctuated so much in the last three years, and it’s also noteworthy that his curveball induced about three percent fewer swings-and-misses last year. Really, I surprise the surprising thing is that his whiff rates didn’t completely tank. I was expecting them to be cut in half or something on the heater and curve, but nope.

Obviously Burnett’s strikeout rate fell off a cliff last year, and at least we know the curveball was a prime suspect. A.J. still gets a healthy does of swings-and-misses, though I suppose his location could have been so bad that when hitters did make contact, they were simply crushing the ball. I’m going to go out on a limb and say … that’s something he and Larry Rothschild should work on.

Hug them, but not too closely
2011 Draft: Opening Thoughts
  • Monteroisdinero

    If ever a pitcher needed first pitch strike 1 it is AJ. The guy could not get #2 over for strikes when he had to in 2010. Hitters knew this of course.

    • Regis

      It seemed to me that, last year, his breaking pitch would always end up out of the zone – if the hitter could lay off the curve then they could tee off on his straight fastball.
      AJ used to kill the Yankees and Sox. I wish that guy would come back but that is just a fantasy right now.

    • http://www.yankeeanalysts.com/ Matt Imbrogno

      I just looked up the data on TL for fun and found this. After an 0-1 count, Burnett threw his four seamer 43.2% of the time and it went for a strike 62.7% of the time. He threw his curve 32.2% of the time in that spot and it went for a strike only 49.2% of the time. The two seamer? 20.8% usage, 47.4% strike.

      • Monteroisdinero

        but with a 1-0 count the curve will not come in for a strike or a batter will just lay off it-not expecting it. Then we have a 2-0 count and….trouble.

  • bonestock94

    I like how much emphasis is being put by the team (and AJ) on his pitching woes last year. I will be very shocked if he doesn’t look better this year.

  • Mike Myers

    Last year I would avoid the “AJ Games” due to the stress it weighs on a watcher. I hope this year will be better.

    So why did we give CC an opt out and not force AJ to opt out? ha

    • Monteroisdinero

      Stressful on catchers too with those 55 foot curveballs.

  • Fair Weather Freddy

    He should work on his change up more. In games where his curveball is not sharp, he needs another pitch to rely on, so hitters can’t sit on his fastball.

    • RL

      How many pitchers added a new pitch to their repetoire after 10 years in the bigs? Not sure its reasonable to expect him to be able to add a ML averate change up if he hasn’t developed one to this point in his career.

  • Rockdog

    I wonder if the problem with AJ last year was falling behind in the count. I’m guessing that he was behind more in 2010 then 2009 or 2008, and that ws the core of the problem. Amazing how much of a difference it makes for a hitter being ahead in the count.

  • Matt

    How about a cutter? AJ’s fastball, while still plenty fast, is too straight, too flat, and too hittable. I wonder if Larry could help him develop a cutter. Unfortunately, the change-up will never be a go to pitch for AJ, but if he can mix his fastball up with a 4-seamer, 2-seamer, and a cutter that would setup his power curve to put away the batters. We’ve seen so many pitchers develop a cutter in their 30s and find success with it.

    • pat

      Your eyes might be deceiving you. AJ had almost perfectly average FB movement in 2010.


      • Matt

        Which then makes me wonder why AJ’s fastball has been worth -14 the past 2 seasons when he’s been averaging 93-94mph on it. When you’re throwing that velocity it doesn’t make sense unless hitters are sitting on it. But even if they are, a fastball with good movement is hard to hit.

        • radnom

          It is probably a combination of poor location and hitters sitting on it when the curveball isn’t working.

  • Monteroisdinero

    Cervelli is telling AJ in that pic:

    “I got a stronger cup for your crappy curveball this year.”

  • aluislugo

    Why can’t he learn to throw a cutter? Seems to me like this would be a nice compliment to his stuff.

  • http://jukeofurl.wordpress.com Juke Early

    I think Burnett will bounce back. But, does anybody know what starting pitcher prep currently is? do the catcher & SP go over the opposing lineup pre-game? ( and why not, if they don’t…) Shouldn’t all these new nano-stats aid them, knowing how, say, Dustin Pud-roya[sic] handles an 0-2 fastball v. a curve? You can know that little cretin fishes for one, but if you can’t get placement – machts nichts. I still say while awareness is key, humans ain’t robots.

    That’s why they play the games & hope your hosses beat theirs.