AL/NL rookies leading in ERA

[micsmith]

Josh Johnson has the best ERA in the majors, excepting Frncisco Liriano. He has to be, far and away, the leader for the NL ROY. But, my question is: When was the last year a rookie lead the NL in ERA and a rookie led the AL in ERA?

[yankillaz]

In 1951 when rookie Chet Nichols lead the NL with a 2.88 clip, while in the NL Saul Rogovin played his first full-season (i don't know if he was a rookie, he had 46 innings only prior to this) and led the AL with 2.78.