As with most HOF arguments it's a peak vs. longevity thing. If you care about peak, then it's hard to beat a gold glove, silver slugger, MVP catcher. Longevity is typically where you accumulate counting stats. Mauer will not really have any impressive counting stats other than times on base, which no one cares about. Also this is where you think about him spending several years as a light hitting first baseman, which is a description a LONG way from the HOF. I personally think if he can add another GG and batting title at first base, it really helps his case. The only player with 4+ batting titles (14 of them) who isn't in the HOF (besides Miguel Cabrera) is Bill Madlock, which um, he's certainly the odd one out on that list. If Mauer just has a couple more mediocre years and retires, I don't think he has enough "good" years to compliment his "great" years, and his "great" years aren't "great" enough to dismiss that.