Below are the first two seasons of a pair of young major league starting pitchers. One is about to enter his third season in the big leagues and the other is coming off of a banner year where he won 19 games, posted a 3.25 ERA, and struck out 225 batters.
Player X Season 1: 22-years-old, 15 GS, 4.76 ERA, 6.64 K/9, 5.05 xFIP
Player X Season 2: 23-years-old, 11 GS, 4.57 ERA, 7.14 K/9, 5.12 xFIP
Player Y Season 1: 23-years-old, 16 GS, 4.63 ERA, 9.07 K/9, 3.39 xFIP
Player Y Season 2: 24-years-old, 7 GS, 4.94 ERA, 7.84 K/9, 4.08 xFIP
Player X was the Boston Red Sox's Jon Lester, Player Y is the Nationals own Jordan Zimmermann.
The comparisons don't stop with their first two campaigns though. Both throw essentially the same repertoire, a low-to-mid 90's fastball with a mid-to-high 80's slider/cutter and a high 70's curve ball. They both had their rookie year interrupted, Zimmermann by Tommy John surgery and Lester by cancer. And both had to battle their way back to their majors from Single A in their sophomore campaign.
Zimmermann is often overlooked in Nats Town, as would any young pitcher hurling in the wake of Stephen Strasburg's hype. This all could end in 2011 though if Zimmermann takes the strides that Lester took in his third season in the bigs.
In 2008 Lester emerged as one of the top left-handers in the American League. The 24-year-old went 16-6 in 210 innings while posting a 3.21 ERA and a 6.50 K/9. That would be a pretty big step for the Nationals righty who has yet to pitch a full season, but if Lester can do it there are a lot of reasons to believe Zimmermann can too. Zimmermann already has a higher strikeout rate, and a lower walk rate than Lester at the same point in their respective careers. Zimmermann also has induced a higher ground ball percentage and has a historically faster fastball.
Of course, there are reasons Lester made the strides he did in 2008. For starters his ground ball percentage improved tremendously, from 34.4% in 2007 to 47.5% the next year. He walked less batters, 2.82 BB/9 compared to a reprehensible 4.43 the year before. Most importantly, he eliminated the long ball from his game, allowing just 0.60 HR/9, allowing his defense to make plays when he wasn't striking out a third of the batters he faced.
The key for Zimmermann to make the transition from prospect to front-of-the-line starter then is his ability to improve. He needs to cut down on the long ball, 2.32 HR/9 in 2010, and needs to regain the effectiveness of his slider. The good news is that players usually see their biggest improvements the year after their Tommy John surgery, meaning if he put in the work this offseason he could come to spring training a changed man, and a force in the Nats lineup.
If he can make the transition that Lester did in 2008, it would be huge for a Nationals rotation that has been in flux since 2005. The club came into the winter with the goal of acquiring a front-of-the-line starter but failed publicly twice. First they were outdone by their division rival Philadelphia Phillies in their attempts to sign Cliff Lee, and then they were flat out rejected by former Royals Ace Zack Greinke.
Zimmermann represents a hope for the Nationals that 2011 won't be a total wash. The club suffered a net loss when they elected to sign Jayson Werth (5 WAR) while letting Josh Willingham (2.7 WAR) and Adam Dunn (3.9 WAR) go, and their starting rotation which was terrible last season has found no upgrade.