Minimum needed to qualfy for the list: 40 IP.
As you'd expect, Mariano Rivera dominates this list. While he's not the leader in ERA, he's the saves leader by a wide margin and he has a scarifyin' 0.793 WHIP.
That said, Grant Balfour is having a sensational run thus far in his 55 IP. There's little skating by on inherited runner data: the guy has simply been unhittable.
More on interleague pitching performances coming soon...
