According to units won this year:
1. Scott Kazmir (Tampa Bay Devil Rays) - 7-3, 3.15 ERA, +8.60 units.
2. Roy Halladay (Toronto Blue Jays) - 7-1, 2.81 ERA, +7.80 units.
3. Tom Glavine (New York Mets) - 8-2, 2.59 ERA, +7.51 units.
4. Curt Schilling (Boston Red Sox) - 8-2, 3.86 ERA, +7.28 units.
5. Gustavo Chacin (Toronto Blue Jays) - 6-1, 5.11 ERA, +7.13 units.
6. Miguel Batista (Arizona Diamondbacks) - 5-2, 4.12 ERA, +6.48 units.
7. Brandon Webb (Arizona Diamondbacks) - 8-0, 2.01 ERA, +5.94 units.
8. Ryan Madson (Philadelphia Phillies) - 5-3, 6.04 ERA, +5.75 units.
9. Bronson Arroyo (Cincinnati Reds) - 7-2, 2.40 ERA, +5.73 units.
10. Tim Hudson (Atlanta Braves) - 5-3, 3.99 ERA, +5.51 units.
Note - I am not saying all these guys are necesssarily underrated but for them to be making these units some gamblers must have them not rated high enough. As you see some of them have high ERA's and you can bet they are getting great run support, so that plays in to these rankings as well. Just threw this out here, copied it from article over at Covers and it though it sort of ties in to this I couldn't make a case for all these guys.