Rank, ERA of Starters (up 15+ spots since 2011)
1. Royals (#29 in 2011)
3. Pirates (19)
5. Orioles (30)
6. Indians (21)
7. Astros (24)
It is very early, and one bad start would cause this to change quickly. It is very unlikely that all, or even most, of these teams will finish in the top 10 of Starters ERA at the end of the year. That said, these are not the same staffs that they had last year.
Some of these teams have added new pitchers, and younger pitchers might be read to make big leaps forward. The Royals, for instance, would seem to have a rotation good enough to avoid being ranked 29th again, but we will have to wait and see.