Zimmermann: Best Rookie Pitcher?

While no rookie starting pitcher has exploded onto the scene a-la-Dontrelle Willis in 2003, MLB fans have been treated to a steady stream of premium young arms getting their first extended looks in the majors. The Cahill’s, Anderson’s, Porcello’s, Price’s and Hanson’s have all gotten plenty of attention. However, another extremely gifted youngster has largely gone under the radar in our nation’s capital. The Washington Nationals may be plagued by a laundry list of issues, but Jordan Zimmermann ’s starts are turning into must-see TV (well, MLB.TV) for this fan.

Since making his debut April 20th, the Division III Wisconsin-Stevens Point product has posted a 3.55 Fielding Independent ERA (FIP). Zimmermann has punched out an excellent 8.91 batters per nine innings, while limiting the free passes with 2.55 BB/9. Among starters tossing at least 60 innings, the 23 year-old righty has the 23rd-best FIP. His 3.45 K/BB ratio ranks 18th, just ahead of Florida’s Josh Johnson. Yet, Zimmermann’s ERA sits at 4.65. What’s the deal?

Unfortunately, the 6-2, 200 pounder is backed by the worst defensive squad in baseball. The Nationals rank last in team Ultimate Zone Rating and 29th in Defensive Efficiency (the percentage of balls put in play that are converted into outs). While a strikeout pitcher like Zimmermann isn’t as harmed by lousy D (he doesn’t put the ball in play as often), his BABIP sits at .331.

In terms of the things Zimmermann has more direct control over, he has been superb. Opposing hitters have hacked at pitches outside of the strike zone 28.4% of the time (24.9 MLB average). Zimmermann is inducing contact on the first pitch or getting ahead of the batter 0-and-1 often. His First-Pitch Strike% sits at 66.3, well above the 58% MLB average. His rate of first-pitch strikes places 7th among starters tossing at least 60 frames.

Zimmermann also comes equipped with a power pitcher’s arsenal. He utilizes a 93 MPH fastball, hard mid-80’s slider, high-70’s curveball and a mid-80’s changeup. While the fastball (-0.53 runs/100 pitches) and curve (-0.43) have been ordinary, Zimmermann’s slider (+1.65) and changeup (+2.08) have been wicked.

You wouldn’t know it from a cursory look at his numbers, but Jordan Zimmermann has pitched like an ace during his rookie season. He’s striking out nearly a batter per inning, limiting the walks (his 53.4 Zone% is about 4 percent above the MLB average) and possesses stuff that compares favorably to any other rookie in the majors. Time will tell who becomes the most successful out of 2009’s batch of rookies, but Zimmermann is certainly deserving of a place in the conversation.