'Best-of' lists define the college football offseason. Who are college football’s best players? Who are college football’s best teams? Who are college football’s best coaches?

But the sport is a little more complicated than that. Remember, there are 11 players on the field at a time for each team, and depth plays a huge for each program as it rolls through a season. Injuries happen and stars inevitably go down.

Think of Wisconsin last year. Star linebacker Jack Cichy tore his ACL in fall camp, but the Badgers, due in large part to a deep stable of talented linebackers, endured to finish second nationally in total defense. Alabama too suffered a myriad of linebacker injuries last season but held on for a national championship because of depth.

This week in Thursday 10, we’re taking a look at the best units in college football on a positional basis. That doesn’t just mean the best player in the country per say or even the best pairing, it also factors in depth.

With that in mind, let’s take a look at the best positional units in the nation heading into 2018.