Where Have A.J. Burnett’s Strikeouts Gone?

Following Wednesday night’s disastrous start (3.1 innings pitched, two homers, and more walks than strikeouts) A.J. Burnett has now faced 382 batters on the season. Two hundred batters faced is the amount Pizza Cutter established as the threshold for strikeouts/plate appearances to become a reliable metric during a single season. That’s worth noting because Burnett’s strikeout percentage sits at 16.5%. Over the last three seasons, he struck out 23.7% of batters faced; over the last five that number is 23%; for his career it’s 21.7%. As it stands, the only season in which Burnett struck out batters at a lower rate than he is currently was way back in 2000. That year, he struck out 15.7% as a 23-year-old

When Burnett signed with the Yankees, the expectation was that his numbers could actually improve. He was battle tested in the rough American League East. More important than battled tested, though, he was successful. His xFIP had ranged from 3.55 to 3.64 over his three-year stint with the Jays, and a move to the Yankees meant he would no longer have to face a lineup consisting of multiple Hall of Famers on numerous occasions each season. That hasn’t been the case, though.

It was probably unrealistic to expect Burnett to improve on his whiff rate, which was over 10% in 2008, but that figure declined to 8.2% in 2009, and sits at 7.1% in 2010. A once raging fastball, sitting in the upper 90s on some occasions, has retreated in velocity. Pitchfx has its average velocity sitting just about 93 miles per hour, with empty swings occurring under 6% of the time. The only pitch Burnett is actually having batters miss often is his knuckle curve (12.5%). Compare that to last season and the only noticeable changes have nothing at all to do with his velocity being down. He’s actually getting more whiffs on the fastball and fewer on the curve.

That would suggest the decline is not entirely due to his velocity, which leaves predictability and location as the other potential culprits. The curve becomes Burnett’s go-to pitch when he reaches two strikes. With the exception of 3-2 counts, Burnett tosses his bender more than 50% of the time on each count. This doesn’t differ too much from 2009, when he threw it 60+% of the time on 0-2 and 1-2 and 48% on 2-2. This usage pattern actually resembles his 2008 pattern more than anything.

This would lead to a question of whether it’s Burnett’s location of the curveball that’s problematic. In 2009, the pitch was swung at under 40% of the time and resulted in a strike nearly 60% of the time. In 2010, however, the swing rate has remained static, while the strike rate has dipped to a little over 51%. That’s not a radical shift, mind you, but a big enough one that it alters Burnett’s ability to succeed. If batters are able to hold off on the inevitable avalanche of curveballs that dive below the zone on two strike counts, that means Burnett will have to beat them with his fastball or sinker, a combination of which hasn’t resulted in a positive run value since 2007.

The most troubling statistic associated with Burnett is that 40% of his strikeouts have come against the Orioles and Indians. Those starts account for a little more than 20% of his starts this season.

We hoped you liked reading Where Have A.J. Burnett’s Strikeouts Gone? by R.J. Anderson!

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Dirty Water
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Dirty Water

“The most troubling statistic associated with Burnett is that 40% of his strikeouts have come against the Orioles and Indians”

Isn’t it also true that CC has only beaten the Orioles? So, essentially, the Yanks are relying on Pettitte, Hughes and Vasquez to win important series?

Oh, oh. Someone better go inform Kevin. Looks very ugly.

Zack
Guest
Zack

He’s picked 4 of his 7of Ws against the O’s, but we all know by now that W/L records are flawed. He’s had good games against the Phillies, Red Sox, A’s, Rangers, and Rays. And then 3 games where he’s given up 5ER, 1 game where he gave up 6ER, and 1 game he was pulled at 4.2 IP because of rain delay.

Dirty Water
Guest
Dirty Water

True, but don’t forget this is FG where you’re posting. CC’s K rate has gone down 3 straight years, and that means he’s godawful, the end is near.

frank
Guest
frank

This is purely anecdotal from watching him pitch last year… but he seemed to throw more curveballs for strikes early in counts last year (I have no idea if the stats back that up – I’m not talking just # of curveballs but curveballs in the zones).

If he’s missing with the curveball early in counts, it’s easier for hitters to lay off it when behind or even in the count (1-2, 2-2). If he shows a team he can command it for strikes early in the count, then when he throws it with 2 strikes batters have to give it a bit more respect.

He also seems to be throwing more 2 strike curves way out of the strike zone (bouncing them to the point where hitters don’t see the pitch as potentially a fastball strike out of his hand). He’s at his best when the catcher is catching that low curve just barely above the ground (especially to lefties) or trying to do a backdoor curve over the outside of the curve.