Oklahoma State is the 8th ranked pass efficiency defense in the nation if you wanna nitpick.
From a pure numbers/averages standpoint (yes, I know these can sometimes be deceiving, but it's a pretty good overall look):
PAC-12
Average yards allowed per game = 432 (250 passing)
Average points allowed per game = 28 (1.79 passing TD)
Average pass efficiency defense = 138.8 rating, 62% completion, 7.33 yds/attempt
Andrew Luck: 264 passing yards/gm, 2.9 passing TD/gm, 70% completion, 8.5 yds/attempt, 167.5 rating, 35 TDs, 9 INTs
BIG 12
Average yards allowed per game = 422 (253 passing)
Average points allowed per game = 30 (1.67 passing TD)
Average pass efficiency defense = 131.5 rating, 60.7% completion, 7.2 yds/attempt
Robert Griffin III: 333 passing yards/gm, 3 passing TD/gm, 72.4% completion, 10.8 yds/attempt, 192.3 rating, 36 TDs, 6 INTs