The New And Improved Jon Lester

As the grains in the hourglass slip away toward the trading deadline, Jon Lester has become the most focused-upon target of buyers. As recently as a month ago, this didn’t seem to be a particularly likely scenario, but the surge of the Tampa Bay Rays and the plunge of the Boston Red Sox has caused the wheel to spin from David Price to Lester. While Lester has been exceptional this season, his 2013 performance would be characterized as no better than solid, and he was one of the game’s biggest disappointments in 2012. What has happened to bring Lester from there to here, and is his current form sustainable going forward?

I got my first baseball job in the fall of 2002, an amateur scouting position covering the northeastern US for the Milwaukee Brewers. I had the privilege of working with a part-time scout by the name of Eddie Fastaia, who was based in Brooklyn. Eddie helped me get my feet on the ground, and is a tireless worker, indispensable asset, and personal friend. He had contacts everywhere, and knew where to find the prospects, winter, spring, summer or fall. One of the leading summer programs in the Northeast was – and is – the Bayside Yankees program, based in the New York City area. In general, their lineup was composed of top Northeast prospects, with the occasional kid from elsewhere in the country mixed in.

In the summer of 2001, Eddie was covering the Bayside Yankees, and his ears perked up when he noticed an impressive-looking lefthander taking the mound for Bayside. He prided himself on knowing the prospects from his area from a very young age – and he had no idea who this kid was. He quickly touched base with the Yankee coaches, and found out that the ringer was a kid from Tacoma, Washington, named Jon Lester. On one hand, Eddie was disappointed, as he thought he had a local find on his hands, but always the team player, he quickly notified the office of this kid’s presence, and his exceptional performance. In the several years that I worked with Eddie, he told his Jon Lester story to me many times – scouts do not forget the moment when they come across a really good one that they had no idea they were about to see.

The Red Sox tabbed Lester in the 2nd round of the 2002 draft, paying him like a first rounder, and the rest is history. He rose steadily, if somewhat unspectacularly, through the Sox system, going 32-31, 3.33, with a 446/203 K/BB ratio in 483 2/3 innings as a minor leaguer. Those stats look quite a bit more impressive when you consider that Lester always ranked as one of the youngest players at each minor league level, reaching Double-A at age 21 – and striking 163 batters in 148 1/3 innings – and making his major league debut on June 10, 2006, at age 22.

He was an extremely consistent performer throughout his first few seasons with the Sox, and having a pretty strong club behind him made his traditional numbers quite eyecatching. After the 2011 season, Lester’s career won-lost record stood at 76-34, for a ridiculous .691 winning percentage. His worst seasonal ERA+ figure over that stretch was 124. Lester clearly ranked among the very best young pitchers in the game. His stock took a hit in 2012-13, as he posted a dreadful 4.82 ERA in the former season, and bounced back just a little to post a 109 ERA+ in 2013. A year away from free agency, what once appeared to be a certain 2015 bonanza was now at least somewhat in doubt.

In addition to his significant regular season contributions to the Red Sox’ cause, Lester has been an invaluable postseason contributor, going 6-4, 2.11, overall, including a 3-0, 0.43, tour de force in three World Series starts. The Jon Lester of the 2013 postseason was a different cat than the regular season version, and he has kept the ball rolling deep into 2014.

Let’s dig a little deeper into Lester’s 2012-14 performance to find out the keys to his metamorphosis into the monster he has become, by reviewing his 2012-14 plate appearance outcome frequency and production by BIP type data for some clues. First, the frequency information:

FREQ – 2012
Lester	%	REL	PCT
K	19.0%	105	59
BB	7.8%	110	68
POP	9.4%	106	60
FLY	24.6%	81	10
LD	25.2%	104	65
GB	40.8%	109	73

FREQ – 2013
Lester	%	REL	PCT
K	19.6%	103	60
BB	7.4%	101	53
POP	10.0%	133	81
FLY	26.4%	94	39
LD	21.1%	98	41
GB	42.5%	99	44

FREQ – 2014
Lester	%	REL	PCT
K	25.7%	127	82
BB	5.5%	71	16
POP	9.7%	125	76
FLY	27.2%	97	34
LD	20.6%	99	41
GB	42.6%	98	40

The biggest change in Lester’s profile from 2012-13 to 2014 is the large increase in his K rate. Lester’s 2012-13 K rates were the two lowest of his major league career – his K rate percentile ranks of 59 and 60 in those two seasons lag well below the 89-95 range he resided within between 2009-11 as well as his 2014 mark of 82. Arguably just as important is the dramatic increase in his BB rate this season. After posting higher than average BB rate percentile ranks from 2010-13, it has dropped precipitously to 16, by far a career best, in 2014.

Lester’s batted ball profile has changed quite a bit as well. He began his career with a fairly significant ground ball tendency – from 2008 through 2012, his grounder rate percentile rank ranged from 63 to 87. As that grounder tendency has waned, Lester has begun to induce popups at a better than MLB average rate, with his popup percentile ranks ranging from 60 to 82 between 2011 and 2014. Lester is one of the rare pitchers who combines a high popup rate with a low fly ball rate – his fly ball percentile ranks have ranged from 10 to 39 since 2008.

So what we have is a high K guy who lost that touch for two seasons, and a one-time ground ball guy who has gradually morphed into a popup generator without developing a fly ball tendency. That’s just the frequency data, though. Let’s take a look at the production by BIP type allowed by Lester in all three seasons, both before and after adjustment for context, to get a better feel for the batted-ball authority he has allowed:

PROD – 2012
Lester	AVG	OBP	SLG	REL PRD	ADJ PRD	ACT ERA	CALC ERA	TRU ERA
FLY	0.424		1.065	202	142
LD	0.585		0.775	87	95
GB	0.213		0.257	87	86
ALL BIP	0.338		0.550	113	103
ALL PA	0.268	0.325	0.436	109	101	4.82	4.37	4.05

PROD – 2013
Lester	AVG	OBP	SLG	REL PRD	ADJ PRD	ACT ERA	CALC ERA	TRU ERA
FLY	0.325		0.755	114	100
LD	0.608		0.800	86	100
GB	0.240		0.279	108	116
ALL BIP	0.318		0.488	95	99
ALL PA	0.249	0.306	0.383	93	96	3.75	3.60	3.71

PROD – 2014
Lester	AVG	OBP	SLG	REL PRD	ADJ PRD	ACT ERA	CALC ERA	TRU ERA
FLY	0.250		0.615	74	80
LD	0.646		0.873	97	91
GB	0.301		0.325	153	104
ALL BIP	0.324		0.478	96	85
ALL PA	0.235	0.278	0.347	78	71	2.52	2.96	2.67

The actual production allowed by Lester on each BIP type is indicated in the AVG and SLG columns, and is converted to run values and compared to MLB average in the REL PRD column. That figure is then adjusted for context, such as home park, team defense, luck, etc., in the ADJ PRD column. In the three right-most columns, his actual ERA, his calculated component ERA based on actual production allowed, and his “tru” ERA, which is adjusted for context, are all presented. For the purposes of this exercise, SH and SF are included as outs and HBP are excluded from the OBP calculation.

First, the magnitude of the impact of the improvement in Lester’s K and BB rates since 2012 should be noted. Adding his K’s and BB’s back to total BIP caused his overall ADJ PRD to go down by two (from 103 to 101) and three (from 99 to 96) basis points in 2012-13, while adding them back caused it to decline by 14 (from 85 to 71) basis points in 2014.

There is another line item, however, that is arguably just as impactful to his 2012-14 performance. Note the dramatic change in the amount of damage Lester has allowed on fly balls during this period. In 2012, hitters batted .424 AVG-1.065 SLG on fly balls against Lester, for 202 REL PRD, adjusted down to 142 ADJ PRD for context. In 2013, they batted only .325-.755 on fly balls, for an exactly MLB ADJ PRD figure of 100. In 2014, he has improved even further, to .250-.615 on fly balls, for an ADJ PRD figure of 80 once adjusted for context.

Managing fly ball contact is a really big deal in Fenway Park. Using my own park factors based on granular batted ball data, Fenway has a fly ball park factor of 151.1, inflating offense more than any park except for Coors Field. The Green Monster is the primary driver of this, as many fly balls that are routine outs elsewhere become doubles in Boston. Despite this fact, Lester has allowed well less than average actual fly ball production this season, not an easy feat.

It should also be noted that Lester is having exceptional overall success this season despite allowing actual production of .301 AVG-.325 SLG on ground balls, good for a 153 REL PRD figure, though that is adjusted for context – mostly bad luck – down to 104 for context. Lester’s 2014 2.67 “tru” ERA figure is very close to his actual ERA, and represents over a full run’s worth of improvement from his 2012 and 2013 marks.

What, if anything, is Lester doing differently to make these changes possible? Well, his pitch selection has changed fairly dramatically in recent years. He had begun to use his sinker more frequently through 2012, pushing his grounder rate upward, but his swing-and-miss rate downward. Since 2012, he has thrown his cutter (up from 13.3% in 2012 to 24.2% in 2014) and his four-seam fastball (up from 32.5% to 41.1%) much more often, at the expense of his sinker (down from 27.9% to 16.7%) and changeup (from 11.8% to 3.7%). His sinker has by far the lowest whiff rate (4.9% in 2014) of his pitches, and his cutter, with an 11.3% whiff rate, is one of his best bat-missers.

His improvement goes way beyond missing bats, however. After all, his 9.5% overall swing-and-miss rate is pretty low for a guy with his K rate, and isn’t terribly far above the MLB average or his career mark of 9.1%. What is Jon Lester doing to manage fly ball contact so well? Lester is actually getting hitters to hit higher fly balls – by a fairly significant margin – than he has in the past. If you split the exit angle between the upper (bordering popups) and lower (bordering line drives) boundaries of the fly ball categories, the average MLB pitcher will allow a third of his fly balls in the upper region, and two-thirds in the lower region. This is a big distinction, as hitters bat .098 AVG-.234 SLG on fly balls in the upper section, and .380 AVG-.990 SLG in the lower.

In 2012, only 25.9% (36 of 139) of the fly balls allowed by Lester were hit into the upper tier, well worse than MLB average. That percentage rose to 32.5% (53 of 163) in 2013, almost exactly the MLB average, and has now risen to 46.2% (48 of 104 fly balls) thus far in 2014. That’s about as high a “high fly ball” percentage that I have seen from a starting pitcher.

Is there some randomness in there? Sure. While some regression can be expected, this trend is real. Looking a little deeper, we see that 39 of these 48 “high fly balls” were hit off of Lester’s four-seamer or cutter. Yes, Lester is missing more bats this season, but just as importantly, he is spotting his fastball and cutter so expertly that, A) his BB rate is way down, and B) he has suffocated fly ball contact, in a fly ball-friendly environment. What we have seen thus far in 2014, is Lester’s perfect storm, his peak. His many suitors may only be getting him for 10 starts or so, but they are betting on getting something resembling the apex of a very, very good pitcher’s career.

By the time you read this, Jon Lester may have a new uniform. A cursory review of opinions across multiple media platforms reveals quite a difference of opinion regarding what he will command in a deal. The lack of acquiring team control, the assumed likelihood of his return to Boston in 2015, and the elimination of draft pick compensation for rental players leads some to believe that the return may not be that significant. The marketplace will likely say otherwise. It already has, in the case of Jake Peavy, a lesser pitcher with the same acquiring team control who fetched a solid package from the Giants. The Peavy package lacked a consensus impact prospect – expect one or more teams to step up with such a prospect in their pursuit of Lester before the clock strikes midnight… make that 4 PM Eastern.