[the_snooze]

I've always associated single-digit numbers to "skill positions," especially speedsters like WRs, RBs, and CBs. If you're in the 50s and above, I'll assume you're one of the "big uglies" duking it out in the trenches.

[jghn]

At least in the NFL WRs and TEs have traditionally been in the 80s. The shift towards the teens and lower started in the mid-aughts.

[kaesar14]

Specifically a rule change that allowed this - too many teams had 80 numbers retired.

[dpeck]

A lot of LBs in the 40s and 50s. I’d qualify those more as medium sized (but meaner) uglies :)