The easiest way to think about Brian Duensing, tonight's starting pitcher for the Twins, is that he's an average pitcher. Which is to say, he fits right into the Twins' rotations of recent vintage. If there's a thing that makes Duensing Duensing, it's that he gets more ground balls than average. That's about it.
Duensing is often brought up as a successful case of a young pitcher being developed, in part, as a reliever. However, that example depends in part on what you actually think of him. Duensing's advanced macro stats for 2010 reflect his mediocrity. His 4.05 tRA was good for a tRA+ of 105, which means he's 5% better than the average starter. If you prefer FIP, well, his FIP is nearly identical: 4.03.
The one odd thing about Duensing is that, despite being a guy that the Twins love, he doesn't quite fit their mania for strike throwing. Duensing's BB% in 2010 was 37.5%, which is actually slightly above average. Still, he managed to time his balls well, because he nevertheless managed to walk fewer men than most pitchers (6.5%). I guess he's clutch or knows how to pitch to the score... or maybe he'll start walking more men. Who knows. As might be expected, Duensing isn't terrible at striking men out, but he's not average either, recording a strikeout just 14.4% of the time.
Finally, there's the ground balls. Duensing produced a GB% of 52.3 in 2010. That skill is a little bit wasted in the homer-phobic confines of Minnesota, but it is still good to have. Duensing was extremely good/lucky at stranding men in 2010, which helped to keep his runs allowed down.