I'm not a stat guy by any means but I did do a seasonal comparison between the two not including Mauer's #s this year.
Kirby's averages are BA-318, HR-17, Doubles-34, RBI-90 and Hits-192
Mauer's averages are BA-324. HR-10, Doubles-27, RBI-66 and Hits-137
I know these aren't per ab #s but you can also throw in Kirby's leadership, durability and two rings. I like Joe but (IMO) he's got a long way to go to be put in Kirby's league. jmo