Red Sox Diaries

One of last season's most exciting developments was Jon Lester's emergence as a front-of-the-rotation starter. He had been one of Boston's most hyped prospects--they valued him so much that they refused to include him in the Josh Beckett trade after the 2005 season (but parted with Hanley Ramirez, one of the most exciting young players in the game, and Anibal Sanchez, who threw a no-hitter) and wouldn't deal him in a package for Johan Santana.

He had a strong start to his rookie campaign as a 22-year-old in 2006, winning his first five decisions and giving up two runs or fewer in each of his first eight starts. But Lester's last seven outings were much less impressive--a 7.75 ERA and only two starts of longer than five innings. Boston shut him down prematurely that season after doctors discovered that he had a treatable form of cancer called non-Hodgkins lymphoma, and he returned in late July of the next season to post a 4-0 record down the stretch and win the clinching game of the World Series. Through parts of two professional seasons, Lester's career record was 12-2 including playoffs.

But that record was pretty misleading if you looked at it closely--in 11 of his 26 professional starts, Lester gave up 4 or more earned runs. Yet the offense bailed him out time and time again, and he had a 2-2 record in those games (rather remarkable when you think about it). His strikeout-to-walk ratio also hinted at trouble, hovering around 1.50, and upon his return in 2007 he served up 10 home runs in 61.1 innings.

Of course, he was also very young and was coming back from cancer, so maybe that analysis is too harsh. Anyway, the point is that last season was the first time Lester really lived up to his potential and showed why he was held in such high regard. He also had an 11-1 record and 2.49 ERA at Fenway Park, which is famously difficult on lefties because of the Green Monster.

There was obviously a lot of positives that came out of last season for Lester--the no-hitter in mid-May against Kansas City, a homer rate that dropped by more than half, and so on--but I saw two slightly troublesome trends: a somewhat low strikeout rate (just 6.5 Ks per 9 innings, versus an 8.3 rate in his minor league career) and a workload that was far greater than any he had previously handled.

One of Sports Illustrated's baseball columnists, Tom Verducci, went into the second point in detail yesterday. He posted his annual report of pitchers who are at risk of the Year After Effect--basically, the idea that pitchers who throw significantly more than they are accustomed to are more likely to have injury problems the next year. Who topped Verducci's list? Jon Lester, whose 237 innings last year represented a jump of greater than 50 percent from his previous career high.

In the piece (which you can read here), Verducci says that, of the 24 pitchers who he has flagged over the past three years, 16 of them spent time on the DL the following season. Only one stayed healthy all year and lowered his ERA.

So, how will Lester's arm hold up? Verducci mentions that Lester might be safer than most, since he's older than most of the guys on the list and at 6-foot-2 is a pretty big guy. He also quotes Boston's pitching coach, John Farrell, who said that Lester was showing no signs of breaking down and in fact had better velocity this spring than he did a year ago. But on the other hand, Lester threw 100+ pitches in 21 of his 37 starts last season, and only six times did he throw fewer than 90. A lot of his outings were in high-pressure situations, too.

Out of curiosity, I checked out who baseball-reference.com listed as Lester's most similar counterpart at this stage in his career (check out an explanation of how Similarity Scores work here.) It was Tim Hudson, who threw about 80 more innings when he was 24 than he did when he was 23--a similar margin to Lester's 24-year-old season over his previous career high. Hudson proceeded to throw even more innings the next year and made at least 27 starts in each of the following seven seasons.

Hopefully that bodes well for Lester in 2009 and beyond. Then again, Hudson did end his streak of durability after undergoing Tommy John surgery to repair his elbow last season. Red Sox management has to proceed with caution.

--Danny Daly (ddaly06)