One of the better stories of the 2008 season was the maturation of Jon Lester into a pitcher very much to be reckoned with.

Fire Brand sponsors his Baseball Reference page with this quote: “He beat cancer. He beat the Rox for the World Series. He threw a no-hitter. What’s next… Hall of Fame?”

There are three pressing questions when attempting to evaluate Lester’s chances for 2009: control, workload and xFIP.


In 2008 at the age of 24, Lester threw 210.1 innings and won 16 games to go along with six losses. He checked in at a 3.21 ERA with a 1.27 WHIP, making significant strides towards arresting his control issues, which had been the only thing holding him back.

Take a look at how much he improved his control:

Year BB/9 K/BB
2006 4.76 1.40
2007 4.43 1.61
2008 2.82 2.30

That’s a significant increase in control, especially considering he didn’t throw the cutter predominantly until 2007. (Threw it 2 percent of the time in 2006, 22 percent of the time in 2008 and 2008.)

Only time will tell if Lester’s control will hold up. There’s currently no simple way to identify if a player’s control is legitimate or not. This will be one of the major components of Lester’s arsenal to watch in the early going.


Lester pitched 26.2 innings in the postseason for a sum of 237 total innings in 2008, a 45 percent jump from 2007 when he pitched a cumulative 163 innings.

The Verducci Effect calls for a significant risk of injury for young pitchers who experience of jump of 30 or more innings in their previous two seasons. Considering Lester jumped 74 innings, this makes him a prime candidate for injury.

How worried should we be? A 45 percent jump in innings is rather drastic, but Lester may be the exception to the norm. Remember, Lester was still recovering from his bout with cancer and underwent a strong off-season regimen to prepare him for the season. The further he got away from chemotherapy, the stronger he seemed to become.

A lot of subjective analysis for his workload here, so we’ll have to wait and see. I will say this, and this should come as no surprise: The Red Sox are aggressive about making sure each pitcher does not get hurt and schedules “breaks” for them as the season goes — whether by skipping a start or putting them on the disabled list. With Clay Buchholz, Charlie Zink and Michael Bowden in Pawtucket, I’m not concerned.


Lester’s xFIP is not as impressed with Lester’s 2008 than most of us were. First, an explanation of FIP and xFIP:

Fielding Independent Pitching, a measure of all those things for which
a pitcher is specifically responsible. The formula is
(HR*13+(BB+HBP-IBB)*3-K*2)/IP, plus a league-specific factor (usually
around 3.2) to round out the number to an equivalent ERA number. FIP
helps you understand how well a pitcher pitched, regardless of how well
his fielders fielded. FIP was invented by Tangotiger.

Expected Fielding Independent Pitching. This is an experimental stat that adjusts FIP
and “normalizes” the home run component. Research has shown that home
runs allowed are pretty much a function of flyballs allowed and home
park, so xFIP is based on the average number of home runs allowed per
outfield fly. Theoretically, this should be a better predicter of a
pitcher’s future ERA.

In layman’s terms, xFIP takes all the statistics a pitcher is primarily responsible for and adjusts it for league average. Lester’s ERA and xFIP over the years:

2006 4.76 5.35
2007 4.57 5.25
2008 3.21 4.19
Okay, so his xFIP isn’t as exciting as his ERA. Two points, though:

  • xFIP does like Lester’s progression from 2007 to 2008, as it decreases over a full point. This is significant.
  • This just underscores how important defense is to a pitcher. The difference between ERA and xFIP largely rests on the defense.

Considering the Red Sox have been among the league’s best defensive teams since they put an added focus on defense in 2006, it comes as no surprise that Lester’s ERA is lower — signifncantly lower — than his xFIP. Of course, it’s not just the defense that comprises the difference, but it is a large part.

Take Carlos Silva into account. With a fine defense behind him in the 2007 Minnesota Twins, he posted a 4.19 ERA and 4.67 xFIP. In Seattle in 2008, we all know how atrocious he was: a 6.46 ERA. Ah, but his xFIP? 4.74. Significant difference, as it is widely held that the Mariners hold one of the worst defenses in baseball, especially in the infield where Silva makes his living.

So, will Jon Lester regress? It’s hard to say, but it’s definitely possible. His workload is a screaming red light while we don’t know what to make of his improved control.

We’ll just have to wait and see.