Lookout Landing: AJ Just As Consistent As Pettitte

When AJ Burnett allowed 4 runs in the first inning last night, I received a number of angry text messages from friends. Most of them were along the lines of “I told you he cannot be trusted!!! He is way too erratic and inconsistent!!!” My response was the same as it has been all year: this is just a narrative that was created due to his personality, and the numbers do not support that point. Because he has always been seen as flaky, people take every poor start as a sign of some inner failing which suggests that he cannot be trusted.

A rudimentary look at this season’s game log showed that AJ had 4 starts this season where he totally blew up, meaning he pitched fewer than 6 innings AND allowed more than 3 runs, a “reverse” quality start. These are game where the starter provided neither length nor quality. CC Sabathia also had 4 such starts, while Andy Pettitte had 5. Just as a point of reference, Zach Greinke had 2, Justin Verlander had 4, and Felix Hernandez had 4. By this very rough metric, AJ Burnett was just as consistent at his own level of performance as these other, more highly regarded pitchers were. Lookout Landing provided a significantly more scientific look, and reached the same conclusion:

A.J. Burnett, Career: 54.6 average game score, 17.2 standard deviation
Andy Pettitte, Career: 51.4, 17.2

A.J. Burnett, Yankee: 53.3, 17.0
Andy Pettitte, Yankee, 2007-2009: 49.8, 16.3

And, for the hell of it:

C.C. Sabathia, Yankee: 58.1, 17.8

For a little perspective, Felix’s numbers this year came out to be 60.8 and 16.5. Felix in 2007, meanwhile, came in at 52.1 and 18.7.

A.J. Burnett has a reputation for being wildly inconsistent, throwing three ugly innings in one start and then spinning a shutout the next. That angle has, naturally, been played up in the postseason, as the Yankees “can’t be sure what they’ll get” out of one of their more shiny investments from game to game.

The people saying that last bit are correct. The point they’re missing, though, is that the same thing could be said for pretty much every other pitcher in baseball. Starters are inconsistent. When so much depends on the weather, the opposing lineup, and the defense, it isn’t realistic to expect a guy to go out and have the same game every turn. There will be variation. And though Burnett is far from being the most consistent pitcher in the league – Roy Halladay, for one, is more reliable – people need to get over the notion that his body is some sort of exceptional binary system that on any given day will either suck or excel. He made two starts lasting fewer than five innings this year, to Pettitte’s three. He made five starts in which he allowed 6+ runs, to Pettitte’s four. And 71% of his starts this year have generated a game score between 40 and 70, to Pettitte’s 62%. Pettitte, of course, is just standing in as an example, as someone most “baseball people” will tell you is consistent. As it turns out, it seems he’s not really much more consistent than the guy who used to wear rings in his nipples.

That’s right. The standard deviation in Game Score for Burnett and Pettitte over their careers are equal. So the next time someone tells you that Andy Pettitte is consistent while AJ Burnett is a blowup waiting to happen, you can call them out on it. It is just a narrative construct, and a conclusion that has no basis in objective fact.

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