The Baseball Reference HOF metric is a complicated system, based on a combination of stats, postseason success, and awards won. It should be noted that though Hoffman retired as all time saves leader (broken by Rivera before he became HOF eligible), he only led his league in saves twice. And because there are so few relievers in the HOF to set a standard, they don't have a great formula in place for relievers. Also, these numbers have no real bearing on who gets in; it's merely a way of comparing careers to guys who are already in.
I'm going to reevaluate how I collect after the new year. It's just getting way too expensive for the new stuff. Sometimes I just want to buy a pack, not a whole box or even blaster.