Ace in the Hole: On Jon Lester's Puzzling Decline

Jon Lester has become an enigma wrapped in a mystery, surrounded by a puzzle, encased in a conundrum. It was just two seasons ago that Lester finished fourth in Cy Young voting, but that time has been heavily overshadowed by his struggles in 2012 and his role in the September 2011 collapse and subsequent "chicken-and-beer" scandal. Despite the fact that Lester is just 28 years old, many people seem to believe that his days as an ace pitcher are behind him.

Certainly, 2012 was brutal. His 128 ERA- was easily the worst of his career as was his 4.11 FIP. He was uncharacteristically home run prone, letting 13.9% of fly balls find the stands. He also got fewer ground ball than in the past two seasons, but the real issue was strikeouts. From 2009 through 2010 Lester was second only to Tim Lincecum in K/9 and K%. His strikeout rate dipped in 2011 to 8.6 K/9 and then again in 2012 to a mere 7.3. His walk rate dropped as well in 2012, helping him some, but the lack of punch outs may be enough to drop Lester from the upper tier of major league pitching to simply being a solid number two or three starter. Given his $11.625M salary for 2013, that is still decent value, but almost no possible free agent signing would impact the Red Sox as much as Jon Lester’s return to ace-level production

The downward decline in his strikeout rate is a concern but last season and September 2011 really have swung perceptions too far. His BABIP and HR/FB rates are not going to remain where they have been during that time period and his Left-On-Base% was ridiculously low last year, inflating his ERA well above what his peripherals predicted. Some may argue that these numbers are not simply the product of random variation, but it is difficult find evidence specifically illustrating a cause for such things. With the wide levels variation typical in such metrics, it is likely that he will see more normalized LOB%, BABIP, and HR/FB rate in 2013 and that alone would be a huge improvement. In 2008, the lefty had just a 6.5 K/9 rate and with slightly better than average results in these three areas he posted a 3.21 ERA backed by a 3.64 FIP and a 4.03 xFIP. That is not ace-level production, but it is very good. Nothing about Lester’s 2012 season suggests that this is an unreasonable projection. Will he be better than that? I think there is reason to believe he will.

Among the issues plaguing Jon Lester last year was a loss of velocity on his four seamer from his 2009-2010 peak. This is typical of pitchers with declining strikeout rates. Off-speed pitches may get the swings-and-misses but the fastball needs to be effective for most hurlers to rack up K's. The strange thing here though is that Jon Lester only lost velocity on his four seam fastball. He lost nothing on his sinker, which was even a hair faster in 2012 and cutter has also maintained it’s velocity.

This is very strange to me. In terms of arm action, there is little difference between a four seamer and a two seamer. The four seam grip lends itself to more velocity and a "rising" effect, where as the two seamer is slowed by its breaking action toward the arm side. For the four seamer to lose velocity while the two seamer holds doesn’t follow. If this decline in fastball velocity is really a sign of overall decline in Lester’s ability it would be likely be uniform across these three pitches. Josh Beckett’s velocity decline has been essentially uniform. The same is true of Roy Halladay, Felix Hernandez and most of the other pitchers who have seen a decline in velocity recently.

The decline in fastball velocity is a concern but it should not alarm us as much as with those other pitchers. I think this tells us he has a mechanical issue to work out. Given the persistence of his velocity in his other offerings, Lester may well be able to make adjustments to restore his four-seamer’s zip. That alone may not bring Lester back to the level of an ace, but it would help the cause a great deal. His fastball had regularly been an above average offering by pitch values, but last season it cost him over 7 extra runs. The improvement in his walk rate may be the result of working more in the zone with his sinker and fastball. Of the two, it the four seamer that needs to get whiffs in the zone. An improvement in his fastball velocity may also help separate it from his cutter, helping that pitch as well.

An improved fastball is not the only path back to the Cy Young conversation for Lester either. His walk rate fell below league average for the first time since 2009 this year and though his strikeout rate has dropped, it still remains better than it was in his first seasons, when he was an effective pitch-to-contact guy instead of a dominant strike out pitcher. If Lester were to drop his walk rate even further, it would take only the slightest rebound in his strikeout rate to make him a left-hand version of Roy Halladay. That may be very different from his previous '09-'10 Tim Lincecum-style game, but it is still ace stuff. Personally, I think he will meet in the middle. Maintaining, but not improving upon, his sub 3 BB/9 rate, but also managing to pull his strikeout rate up closer to the 8 K/9 range with some restored four seamer velocity. With normalized home run rates, that is a dominant force for any rotation.

For Lester, it has been two years, two different pitching coaches and a decline in strikeouts without a solid explanation why. His frustration with his own poor results was visible throughout through 2012, to the point of becoming an annoyance. John Farrell is back now and whether or not he can correct the mechanical side of things (which is not really his charge), he can certainly help Lester mentally. All of the tools that made him one of the best pitchers in the game are still there. I think we see Jon Lester’s name mentioned in Cy Young articles again and possibly even in this upcoming season. He is too young and too talent to remain an underachiever.