The Twins allowed 804 runs last year. Their pitching staff was last in the Majors in K/9, 29th in ERA and 29th in WHIP. But they were also last in BABIP, suggesting that things might bounce better for them this year. Their FIP (4.30), xFIP (4.33) and SIERA (4.27), though still among the worst in the league, indicate the pitchers deserved better than their 4.60 team ERA. Were they to pitch precisely as poorly in 2012, they could be expected to allow 45 fewer ER over the same number of innings.
The defense, somewhat surprisingly, wasn't terrible in terms of range. UZR/150, for example, has them at just -0.4 R for the season. What killed them were errors; they were 28th in errors and fielding percentage. The 80 unearned runs they allowed were by far the most of the Gardy era. Over the last 10 seasons, they've averaged between 50-60 UER. Cutting back on errors is something the Twins can control, and with the additional emphasis they're placing on fundamentals this spring, I would expect them to reduce their mistakes by about 1/3. Simply replacing the abysmal play they got at SS with Jamey Carroll's excellent career averages at the position would eliminate 19 errors and 13 UER.
On the run prevention side of the ledger, if you give the Twins' pitchers a 4.30 ERA over 1450 IP (a roughly league average total), they will allow 693 ER. If you assume that the more focused and slightly upgraded defense will cough up a more typical 55 UER, you get a total of 748 RA.
The offensive side is clouded by lingering injury concerns to some key players. But until I hear reports to the contrary, I'm going to assume that everyone is healthy, and therefore ready to contribute at the levels they've established in recent years. The exception is Morneau - I don't think it's reasonable to expect him to return to the MVP-caliber play he displayed before his concussion.
Below is a table which builds a simple formulation of runs created: (H+BB-CS)x(TB+.55SB)/(AB+BB). The numbers I'm projecting for the starters are based on the stats from their last 3 healthy seasons, prorated over the number of ABs they racked up in a typical year. Span's averages go from 2008 up to the point of his concussion; Doumit's and Casilla's include 2008 since they missed so many games between 2009-2011. I'm throwing out Mauer's 2011 as an injury aberration and using 2008-2010 instead. With Morneau, I'm also throwing out 2011, but estimating only 75% of his 2008-2010 production over 140 games. I'm only using Major League stats for Valencia and Revere.
The starters account for about 77% of the total ABs the Twins had in 2011. The remainder will go to the bench, which I assume will be Butera, Nishioka, Plouffe and Hughes, or similarly unimpressive players. Whoever comes up from Rochester will also be thrown into that pool. I'll give that cast of characters a 23% share of the Punto-esque numbers the Twins hitters as group posted last year (.247/.306/.360). The results:
729 runs scored. 748 runs allowed. That differential should result in around 80 wins. With no improvement from the pitching staff, and with Morneau hitting something like .225/.299/.397 over 140 games.
From there, the upside is considerable. What if Baker is healthy enough to take Diamond's starts? Subtract 7 ER. Or if Zumaya can apply his 3.05 career ERA to Nathan's 44.2 IP? Subtract 9 ER. What if Revere improves his average to .280? Add 5 RC. What if Morneau is 80% of his former self? Add 8 RC.
The 2012 Twins don't look like they're going to be a very good team, but they shouldn't suck, either. As long as they aren't unlucky and can put their best guys on the field about 3/4 of the time, they should be around .500. I wouldn't expect any less of them.