Can Lester Return to Form?

Now three years removed from a strong 2010 performance (4th place in AL CY), Jon Lester‘s career has reached a crossroads of sorts. A burgeoning ace for years, Lester took a step backward in 2012 when many expected him to take the proverbial reins of the rotation following the unforgettable September collapse and clubhouse scandal.

September 21, 2012; Boston, MA USA; Boston Red Sox starting pitcher Jon Lester (31) gets set to pitch during the first inning against the Baltimore Orioles at Fenway Park. Mandatory Credit: Bob DeChiara-USA TODAY Sports

This past season, Lester finished with a 9-14 record, a 4. 82 ERA, a 90 ERA+ (where 100 equals league average), and posted his lowest strikeout rate since 2008 (7.3 K/9 last year). The sharp contrast of his numbers from last year to 2008-2010, his best three years as a pro, make 2012 look even worse. During that three-year period, Lester averaged a 3.29 ERA,  a 8.7 K/9 rate, and a 138 ERA+. These averages put him in a class as one of baseball’s truly elite starters (his 138 ERA+ was 10th best in the league over that time) and is clearly a far cry from last year’s disaster. However, even with last year’s subpar W-L total and ERA, they fail to tell the whole story of Lester’s season.

A player’s peripherals are the more obscure numbers that give evidence to how they performed and should be expected to perform in the future. These statistics are those that give light to how a player did without necessarily including the results. If that is confusing, hopefully the upcoming examples help.

Last year, Lester had a .312 BABIP or batting average on balls in play, where league average is around .290-.300. BABIP is a statistic that usually indicates if a certain amount of luck-good or bad-was at work and any extremes to either side of the pendulum usually fall victim to the mathematical phenomenon known as regression to the mean. In fact, this is something that is more common than typically observed. A good example of this would be players that experience “fluke” seasons such as Mark Fidrych and Chris Coghlan, in which they play over their head due to various benevolent influences. Over time, as sample sizes increase, we as fans and analysts get a better idea of players and their talent level.

In any event, Lester’s increased BABIP reveals a solid amount of differentiation from his career norm, and thus should return closer to his career average. Furthermore, having injuries to solid defensive players such as Dustin Pedroia and Will Middlebrooks further suppressed Lester’s abilities to get outs on balls put in play. With these key injuries and the revolving island of misfits behind him, Lester’s numbers suffered as a result.

In contrast to the BABIP spike, many of Lester’s other peripheral statistics remained constant or even improved from his ’08-’10 days. For example, Lester improved his walk rate for the second straight season and his velocity stayed relatively stable from his previous seasons as well. Usually when dealing with decline, one has to wonder if an injury was at hand. That said, generally the two most obvious signs of injury for a pitcher are velocity and control, yet

,

as I already said, Lester’s numbers actually improved in that regard.

Altogether, the evidence continues to point in the direction of last year being closer to a fluke than a trend. I’m not saying Lester will go back to being a top ten pitcher, but I look at him as being a solid option at the front of the rotation for a potential playoff team. Entering his age 29 season,  I’d like for Lester to learn from his experiences and benefit from the good ole’ regression to the mean phenomenon and healthy infield.  Don’t be surprised when Lester is the team’s best pitcher in the heat of a pennant race; he’s still that good.