Yesterday, I took a look at the pitcher with the highest True ERA/ERA differential in the majors: Reds closer Francisco Cordero, whose 2.16 ERA was 2.70 runs lower than his 4.86 True ERA.
If you'd like to take a look at the reasons for this discrepancy, you can check the article out here.
Anyway, today I thought I'd look at the pitcher at the other end of the True ERA/ERA luck spectrum for 2009 and it's none other than Yankees righty Sergio Mitre, whose 50-plus innings in 2009 appeared to go horribly wrong, to the tune of an ugly 6.79 ERA.
Now, True ERA doesn't peg Mitre as an ace, but it does have him at a solid 4.12 mark for 2009. Essentially, he pitched about as well as a fourth or fifth starter is supposed to.
Before getting into what caused the difference, I'd like to briefly examine Mitre's skill set.
Mitre's two big skills are that he throws strikes and gets ground balls. Over his career, he's walked 3.01 batters per nine innings, and an excellent 59.7 percent of balls hit off him have been grounders.
In 2009, Mitre actually had better control than he usually does (2.26 BB/9), and his GB percent (57.8) was still excellent.
Because he gets so many grounders, Mitre has done an excellent job limiting line drives throughout his career, with just a 16.5 percent career liner rate. His 2009 rate of 18.2 percent isn't great, but it's above-average.
Mitre has two main weaknesses: he doesn't get a lot of strikeouts, and when he leaves the ball in the middle of the plate it gets hit hard.
Mitre did a better job with strikeouts than he usually does in 2007, striking out 5.57 men per nine innings, which is acceptable given his high ground ball and low walk totals. However, he did allow 10 homers in just over 50 innings, which made for a very poor 1.74 HR/9 ratio. More on this in a bit.
So what I've established is that the Mitre of 2009 generally got grounders, avoided walks, and got an acceptable number of strikeouts while having some homer issues. That sounds like a 4.12 ERA pitcher, not a 6.79 ERA pitcher.
So, what's the deal with Mitre's 6.79 ERA?
The first clue lies on his .349 batting average on balls in play, which is bad luck-driven given that he limited liners well. Remember, he only pitched a little over 50 innings, so bad luck can really drive an ERA up in small stints. Given his batted-ball profile, Mitre's BABIP should've been about 30 or 40 points lower, and his career mark (including 2009) is .332.
But BABIP alone doesn't account for 2.67 runs per nine innings. Another factor is Mitre's stranded runners rate, which, at 57.5 percent for 2009, is far too low to be anyone's true level of performance. Most pitchers, good and bad, tend to be in the 70-80 percent range.
Mitre's career rate for stranding runners (including 2009) is 65.5 percent, so it's possible he has trouble from the stretch, but even if 65.5 percent is his true level of ability, that's another good chunk of runs off the board if he strands an extra 8 percent of runners.
Finally, there is perhaps the biggest factor at play—Mitre's homer rate.
Mitre struggled, as 21.7 percent of fly balls off him left the park last year. Most pitchers, over long periods of time, wind up in the 7-14 percent range. Mitre's career HR/FB ratio is 14.7 percent, a bit high, but much lower than 21.7 percent.
Again, remember the inning samples at play here. If four of those fly balls off Mitre happen to not leave the stands, he's at six homers in 51 innings, an average 1.05 HR/9 rate, and sorta normal 13 percent HR/FB ratio.
He also probably drops a good run or more of ERA.
This is particularly relevant in Mitre's case because he spent 2009 with the Yankees and New Yankee Stadium is widely believed to be the most hitter-friendly park in baseball, particularly to lefties, who Mitre struggles with.
I don't have visual evidence to confirm this, but I'd bet that at least one or two of those homers wouldn't have been homers outside of Yankee Stadium.
What this means is that Mitre, while perhaps ill-suited to be a Yankees pitcher, is still suited to be a major league pitcher and teams should look past the 6.79 ERA and realize he's still got a nice skill set to be a back-end starter or middle reliever in the majors.
With the Yankees in hyper-transaction mode this offseason, it might be a good idea for a pitching-starved team to call up Brian Cashman and see if he'd like to unload Mitre, who isn't likely to play much of a role on the Yankees in 2010.