February 13, 2012 at 12:27 pm by Ben Duronio under Atlanta Braves, Statistical Analysis
The steady argument between sabermetricians and old school types in regards to Jair Jurrjens has been alive since his second season. Jair posted a 2.60 ERA in ’09, leading many to believe that he is one of the best young starters in the game. His FIP that season was a much higher 3.68, which put his -1.08 ERA-FIP spread the third biggest in the league. Many saber types predicted a regression to the mean, while others expected him to build off of that performance into a perennial Cy Young candidate. To date, neither have been quite right.
Last year, Jurrjens did it again. His ERA sat at another incredible mark of 2.96 while his FIP of 3.99 did not quite agree with the results. Again, his ERA-FIP spread was one of the largest in baseball, ranking fifth in the league, at -1.03. Since the start of his Braves’ tenure, he maintains a spread of -0.48, 16th over that time period.
Because of the two big seasons and the current high spread, many conclude that this is just something Jurrjens can do regularly. It is believed by some that he has the ability to outpitch his peripherals. Often, ground ball pitchers and weak contact pitchers do have this ability. To the extent that they have said ability is unknown. For example, Tim Hudson and Derek Lowe both have ground ball rates at 59% or higher, with Lowe actually having the higher rate. Hudson has a -0.38 spread while Lowe’s is +0.15. Obviously, the conclusion that all ground ball pitchers are misjudged by FIP is not valid, though it is often the case.
Now is that the case with Jurrjens? Of the 173 qualified pitchers since ’08, Jurrjens ranks 78 in ground ball percentage. He is not exactly a ground ball wizard, though that misconception is one that is often assumed. His infield fly rate, a number also often associated with weak contact, ranks 136. Jair’s GB/FB rate also sits in the middle of the pack at 78. Lastly, his line drive rate ranks 53, closer to the top of the league than his ground ball or infield fly rates. Batted ball numbers are still statistics to look at with caution, but over the relatively large sample size of four seasons the bias in their ratings gets at least somewhat mitigated.
So what exactly has Jair done that enabled him to record two seasons with a BABIP south of .270 and spreads better than -1.00? The only conclusion I can wrap my finger around is plain good fortune. In both of Jair’s seasons where he outperformed his peripherals, he finished in the top-5 in left on base percentage.
|LOB%||Jair’s||League Avg||E-F Spread|
Is there some uncanny skill that Jair retains that sometimes allows him to leave men on base at a higher rate than almost every pitcher in the league? I doubt it.
One argument commonly heard is to entirely discount his 2010 year due to injuries. On September 14 of that year, Jair tweaked his knee, which actually resulted in a torn meniscus. He did not start a Major League game after the reported tear. Prior to the tweaked knee, Jair made every start from June 30th until that final start in mid-September. He pitched to a 4.02 ERA over that 14 game span, with 68 strikeouts and 30 walks in 87.1 innings. That equates to 7.02 K/9 and 3.10 BB/9 rates, which are similar to his career numbers. To completely discount his entire year, despite having what seemed to be at least 14 healthy starts during the season, is picking and choosing numbers.
During spring training of that year, Jurrjens reported shoulder issues. He made four starts before his hamstring gave him problems in his one-inning outing against the Cardinals. In those four starts, he had two decent appearances and two poor ones. There is a chance that the shoulder problems he had in the early parts of spring affected those starts — the shoulder may have even led to the hamstring injury by nature of altering his mechanics — but he did have a nine strikeout performance before hitting the disabled list. While his start against the Cardinals can obviously be discounted due to the hamstring injury, assuming the previous four should be looked over is a stretch, in my opinion.
So while Jair did have injury issues in 2010, it is hard to say that all 116.1 innings — roughly 17% of his entire career — should not be included when evaluating his career. After all, his strikeout and walk percentages of 17.2% and 8.4% that season matched his rates from the previous season.
Jair basically has two seasons in which he stranded tons of runners, comparable with anyone in the league, and also posted a batting average on balls in play that ranked among the league’s lowest. There simply is not much evidence to support that this is the type of pitcher that Jair is, due to batted ball rates and the other two seasons in which he started. Simply doing this in two seasons does not make it the standard with which to project performance. While 367 innings is a relatively large sample size, Jair’s peripherals and batted ball rates make the notion that FIP does not judge him accurately seem somewhat inaccurate. Maybe there is something to Jair’s style of pitching that allows him to get better than expected results, but that conclusion is not one I am ready to side with just yet.