I was looking over the performance of the Twins various starting pitchers over the last few years, and I think that Blackburn is seriously under-rated by this site. I recognize that the complaints about his contract related to the fact that they didn't NEED to lock him up, but at the end of the day, I think he's been incredibly valuable.I don't have a good way to calculate performance over a selected period of time (other than manual - do any sites do it easily?), so I've just included a few observations below.
Blackburn - over 3.5 seasons, including 106 starts (660 IP total), he has been paid about $3 million so far (.5m, .5m, .75m, 1/2 of 3 m). He has an era of about 4.3, and averages over IP/GS. Going forward, he'll get about $5 million per year, and can probably be expected to put up an ERA of 4-4.5 over around 200 IP per season.
Liriano, over an extra 5.5 years, has an ERA of 4.0, fewer IP (600), and fewer IP/GS. He's been paid $5.5 million, (currently at $4.5/year). Going forward, expectations depend greatly on whether he'll stay healthy.
Baker has bout 5.5 years in the MLB, being paid about $8 million. His 150 GS get him 6 IP per (900 IP), with an ERA of 4.2. He reliable for 180-200 IP, and his salary will rapidly increase going forward, beginning with $6.5 m next year.
Slowey really has about 3.5 years, including 80 starts, 6 IP/start, and 480 IP total. His ERA is 4.4, and he's earned $3 million. He's never topped 160 IP in a year, and it doesn't look likely in the near future.
Pavano has given the Twins roughly 2 years, $12 million, ERA of 4.1 over 400 IP.
I don't think too many other pitchers really enter the equation over the past 4 years. At the end of the day, I think Blackburn has been as valuable as anyone else, despite us continually talking about his back-of-the-rotation status, and his awful first-half of 2010.