Comparing Brian Duensing

With the recent announcement from Ron Gardenhire that LHP Brian Duensing would be given a spot in the Twins starting rotation to begin the 2011 season, I wondered what could be expected from a full season of Duensing as a starter. Duensing has been successful over the last two seasons posting an ERA of 3.02 with a record of 15-5, but has bounced between the bullpen and rotation. I decided to look for a starting pitcher with comparable numbers and that has been in a similar position (quality of team behind him, competition faced, etc) to get an idea of what we can expect. Here is what I came up with...

What we know about Brian Duensing:
As a starter Duensing has pitched 138.1 innings with a 2.93 ERA and 3.87 FIP, while having pitched 76.1 relief innings with a 3.18 ERA and 4.13 FIP. When you consider Duensing's dominate numbers against left handed hitters (.191 average against) and the reduction of facing same handed hitters as a starter, it is interesting to see that he posted a better ERA and FIP as a starter than as a reliever. It is also important to note that his ERA is considerably lower than his FIP.

Duensing does not strike out many batters (5.49 K/9) so much of his success can be attributed to his solid GB% (50.0%) and low BB/9 (2.77). Mixing and locating a repertoire of four pitches (low-90s fastball, slider, curveball, change) has allowed Duensing to keep the ball on the ground and give his infielders a chance to record an out while not issuing many free passes. When you look at Duensing's improvement in GB% from the 2009 season (3.42) to the 2010 season (2.41), his minor league track record (sub 2.30 through 3 years at AAA) as well as the MN Twins emphasis on not allowing walks, there is reason to believe that an improvement can be made in 2011. Sustaining or improving these rates should continue to bring Duensing success as a starting pitcher.

My comparable:
I wanted to find a pitcher that has found himself in a similar situation to Duensing. To do this I wanted a pitcher in the same division (AL Central) and has spent the majority of his career on a winning team. The statistics that I looked for similarities were GB%, BB/9, K/9 and FIP. Here are the career numbers for the pitcher I selected:
2271.1 IP
Record: 148-110
GB%: 46%
B/9: 2.06
K/9: 5.10
FIP: 4.25

The numbers aren't identical, but they show that the two pitchers are similar in their approach to success. Throw in the fact that my comparable is also left handed with a similar pitch repertoire (high-80s Fastball, Slider, Cutter, Curveball, Change) and I think it is a good comparison. This pitcher has obviously sustained his numbers for a much longer period of time than Duensing, but the idea behind finding a comparable is to project what Duensing could do with similar numbers.

So who is the comparable? None other than Chicago's Mark Buehrle. As a Twins fan I have disliked Buehrle because of the uniform he wears, but respected him for how hard he has worked to achieve the career he has had. Brian Duensing has a long way to go to be considered the same quality of pitcher as Buehrle, but I think the numbers show he has the ability to start showing he can be.