Curtis Martin is, undeniably, an all-time great running back, with very similar numbers to Jerome Bettis. Both were eligible for the first time this year, but neither was selected. 

Now, the question becomes: Who gets inducted into the Hall of Fame first, Martin or Bettis?

For me the answer is Bettis, although the two seem locked in a virtual dead-heat.

Martin is in fourth place on the all-time rushing list with 14,101 yards, 448 more than Bettis' 13,653, good for fifth all time. For his career, Martin averaged 4.0 yards per carry, despite having a reputation as more of an explosive, big-play running back. Bettis' average was 3.9, right behind Martin.

I think what pushes Bettis over the top is his Super Bowl ring, which Martin conspicuously lacks. It's a bit unfair, given that it requires a ton of good fortune to be a part of a Super Bowl team, but the two backs are so equally stacked up, I think this could stand as the one deciding factor.

Other key numbers give Bettis a slight edge over Martin, as well—Martin was a five-time Pro Bowl selection and three-time NFL All-Pro (twice a member of the first team). Bettis was selected for six Pro Bowls, was a two-time All-Pro and was once a first-teamer.

Since these guys are so evenly matched, I think the ring is the thing that seals Bettis' selection in 2012.