Yes, A.J. Burnett is Broken

Well, that may be my stupidest post of the year.

A week ago today, I asked whether A.J. Burnett was broken, as he'd given up as many earned runs in July as he had in any two prior months combined. My brilliant conclusion: 

Burnett's been throwing pretty much the same pitches, at the same velocities, to the same spots of late. However, he's facing tougher opponents than he did earlier in the year, and when batters make contact, they've been hitting the ball harder than in the past. There is also a fair amount of evidence that Burnett's been just unlucky of late, suggesting that he could rebound from his July performance.

So naturally, in his next start, three days later, he didn't make it out of the fifth inning, giving up ten hits and two walks in four and a third innings, charged with eight runs, seven of them earned. The next day, he was put on the disabled list with elbow inflammation. Today we learned that he has a strained flexor tendon, i.e. NOT the torn ulnar collateral ligament that necessitates Tommy John surgery, but still a serious injury, particularly for a guy who's 38. Burnett says that he's not going to go through surgery again, and if he can't come back this year, this is the end of the line for him.

Two thoughts. First, how did I manage to so thoroughly screw up my analysis? Well, as I noted, one of the markers for a physical problem is decreased velocity, and Burnett didn't show that...until his last start. Here's a graph showing his average velocity, by pitch type, for each of his starts in July, courtesy of Brooks Baseball:

Just focus on the solid lines. The velocities for his four-seam (straight) fastball (black line), sinking fastball (gray line), and curve ball (orange line) looked pretty consistent until the two fastballs fell off the table in his last start. He said that his elbow had been bothering him for a while, but also that he, like many pitchers, has dealt with elbow discomfort on and off throughout his career. Something clearly went south in that last start, and I had the misfortune of writing about Burnett shortly before.

Second, if this is the end of the road for Burnett, he'll retire with a 163-155 won-lost record and a 3.99 career ERA over 425 starts, during which he struck out 8.3 batters per nine innings and allowed 0.9 home runs per nine innings. Here is a list of pitchers with 400 or more starts with eight or more strikeouts per nine innings and one or fewer home runs per nine innings, ordered by career ERA:

Rk	Player	ERA	GS	SO/9	HR/9	W	L	W-L%	IP	H	R	ER	BB	SO	ERA+
1	Pedro Martinez	2.93	409	10.04	0.76	219	100	.687	2827.1	2221	1006	919	760	3154	154
2	Roger Clemens	3.12	707	8.55	0.66	354	184	.658	4916.2	4185	1885	1707	1580	4672	143
3	Nolan Ryan	3.19	773	9.55	0.54	324	292	.526	5386.0	3923	2178	1911	2795	5714	112
4	Randy Johnson	3.29	603	10.61	0.89	303	166	.646	4135.1	3346	1703	1513	1497	4875	135
5	Curt Schilling	3.46	436	8.60	0.96	216	146	.597	3261.0	2998	1318	1253	711	3116	127
6	David Cone	3.46	419	8.28	0.80	194	126	.606	2898.2	2504	1222	1115	1137	2668	121
7	A.J. Burnett	3.99	425	8.27	0.86	163	155	.513	2702.2	2490	1315	1198	1087	2484	103

Provided by Baseball-Reference.com: View Play Index Tool Used

Generated 8/3/2015.

Not a bad peer group. That's three current Hall of Famers, and at least two others who have the credentials, in my opinion. No, I'm not suggesting Burnett's as good as the other six; that 103 ERA+ means that his ERA over his career was only 3% better than league average, adjusted for home park, while all the others were a good deal better. But he's been a steady, durable above-average performer who had three of his best years while wearing a Pirates uniform.