Let's look at this from another direction.
For one thing, no one knows who Pat McInally is so, the best score doesn't seem to men jack shot where it is intended in this case; pro football.
20 is average intelligence, regardless of profession.
Teachers average 28
Librarians 27
Receptionists, cashier, firefighter, train conductor are all 21
Janitor is 14
Welder is 17
Engineers are around 30, sales people are 25
So, there's some perspective.
Offensive tackles do better than QB's, 26 to 24
Running backs are going to be janitors at 16-17
Linebackers and DB's are 17-18
Dummies who made great, long careers? Frank Gore, a 6.
Current genius who have done well (or looking like it), Eli at 39, Rogers 35, Wentz is a 40, Kaep is 37. Romo 37, Stafford, 38.
Ben Watson is a TE and a long career, at 48
Fitzpatrick is a 48 and a career journeyman.