When I began looking for realistic ways in which certain Twins players might outperform their projections, the Team had just signed Orlando Hudson, presumably turning an 83-win team into and 86-win team. Subsequent projected standings haven't reflected that gain. Partially that's due to the loss of Joe Nathan. But mostly, it seems to stem from the sketchy history of the Twins' rotation.
For example, Baseball Prospectus put out an updated Depth Chart on Friday that has the Twins scoring 816 runs (sensible, given that they passed 800 R in each of the last 2 seasons, despite having only 6 good hitters in their lineup) but allowing 820, therefore finishing .500. I don't know where they're getting 820 RA. The worst run prevention team of the Gardy era was last year's squad, and they only yielded 765 RA. It's ludicrous to project that this team will be so much worse than that one.
Looking at the depth chart in more detail, it seems that they expect the Twins to allow about 735 ER over 1456 IP, for a 4.54 ERA. That's fine. Last year's team allowed 726 ER over 1453 IP for a 4.50 ERA. The individual projections look reasonable, too. They couldn't be predicting that the Twins will give up 85 unearned runs. Even the ham-handed 2008 team only allowed 70. No, I'm going to ignore their standings and calculate my own Twins record based on their depth chart plus 50 unearned runs. That would give the Twins a +31 run differential, good for a 1st-order pythagorean record of 84-78: precisely where they should be due to the loss of Nathan.
Back to the rotation. I'm comfortable with the quintet of Baker, Blackburn, Slowey, Pavano and Liriano, as I think most Twins fans are. But there are significant question marks attached to them. Slowey has never thrown 200 IP, Baker has just once, Pavano has had only one injury-free season since 2004, Blackburn has yucky peripherals, and Liriano really struggled last year. Consequently, not only are none of them expected to post ERAs under 4.00 (though none higher than 4.80), but none of them are locks to reach 200 IP, either.
That situation invites 265 combined IP (18.2% of the team total) from Anthony Swarzak, Glen Perkins, Brian Duensing and Jeff Manship, all of whom are expected to have ERAs over 5.00. The less the Twins have to rely on these guys, the better off the team will be. I've already gone into Liriano's case at great length, so let's just consider the other guys. Baker is slated for 190 IP at a 4.11 ERA, Blackburn 163 IP, 4.80 ERA, Slowey 157 IP, 4.20 ERA, and Pavano 144 IP at 4.72 ERA. If they all could make it to 200 IP, that's 10 more innings of Baker (5 ER), 37 of Blackburn (20 ER), 43 of Slowey (20 ER) and 56 of Pavano (29 ER). 146 IP that can be subtracted from the other group, nullifying the contributions of Perkins (80 IP of 5.06 ERA, or 45 ER), Manship (54 IP of 5.35 ERA, 32 ER) and 12 IP from Duensing at 5.05 ERA (7 ER).
Having the starters healthy and taking their regular turns saves the Twins another 10 RA. That adds another win to the record. If Blackburn matches his performance from his first 2 seasons (4.04 ERA), if Pavano's ERA lands closer to his xFIP (3.96) from 2009, if Baker can sustain the numbers he had over his final 24 starts (3.67 ERA) for the entire season, things could get even better. That would shave another 44 ER off the projection, raising the differential to +85 and the record to 90-72.
A cursory glance at the new PECOTA pitching cards that came out today makes that sort of performance look very doable. For example, the numbers Blackburn has produced in each of his first 2 full seasons would exceed the 90th percentile projection from PECOTA.
The rotation can definitely be an underestimated strength for the Twins. Health is a big part of the breaks teams get each season. Last season, the rotation had terrible luck in that department. If 2010 turns out better, a solid rotation combined with the division's strongest offense should enable the Twins to put plenty of distance between themselves and their rivals.