I dont know of a bias in general, but many prefer nl pitchers for a very good reason. Nl has no dh, and the league era and whips are lower then al. Every edge helps.
Giambi might be a hair better, although their ops are pretty close. But i prefer Helton in a keeper, 3 years younger, and home field.
Hall of Fame Hero
(Past Year: 555)
Joined: 12 Jan 2003
Bases this season: 4,236
Home Cafe: Baseball
Location: Pearl Jam country, right next door to Nirvana, Soundgarden, and Alice in Chains.