Perhaps the central issue for the Twins chances of being competitive this year is the state of the rotation. It was the rotation that made the Twins look like they would get back into the division race last year going into the allstar break. It was the collapse of the rotation that not only ended that run but was a major contributor as the team slid to 99 losses instead of soaring to 99 wins.
I think it is interesting to look at how Twins pitchers performed the last three years. Here they are ranked by innings pitched (I will get to the reason for using IP later in the post.)
Swarzak 102 (64 as starter)
Duensing 130 (86 as starter)
A typical team will have somewhere around 1440 innings pitched each year. Most of those outs will be made while the starters are pitching. But every out the starters don't get will have to be gotten by some other pitcher. In most cases that is not the next best pitcher, but the least worse pitcher available. As the number of outs the starters get decline, the innings get pushed down the bullpen ladder. Some of the outs may get taken by better pitchers, but they will likely be pitching at below their optimum performance. Most of the innings will be picked up by the last guy in the bullpen.
So those outs have to be gotten by pitchers who fit one of two categories. One is guys who are overworked compared to how they would have been used. The other is guys who otherwise would have been sitting on the end of the bullpen bench, released or pitching in the minor leagues. In general, none of those pitchers are going to be optimal. And the more innings they have to pitch, the worse the team's pitching is going to be.
So in 2011 who might have got those extra outs (61 IP) for the Twins?
Chuck James 10 IP/ 6.10 ERA
Kyle Waldrop 11 IP/ 5.73 ERA,
Dusty Hughes 12.2 IP/ 9.95 ERA
Jim Hoey 24.2 IP/ 5.47 ERA
Jeff Manship 3.1 IP/ 8.10 ERA
Kevin Slowey 14.2 IP/ 4.91 ERA
And that doesn't include any innings pitched by overworked pitchers higher in the bullpen heirarchy.
The point here is that the Twins focus on "innings eaters" for the rotation is well placed. Because a guy who pitches only 134 innings, like Liriano last year, requires you to give innings to a reliever who otherwise would have been at AAA. Its better to have a Pavano pitching 222 innings than even a "lights out" 134 innings from a Liriano combined with 88 innings from someone pitching like Dusty Hughes. Innings pitched is the key determinant of a starter's value.