John Riordan: NFL an enduring and stubborn king in US sport

Since the late 1960s, the NFL has successfully managed to inflate the Super Bowl into a worldwide spectacle, its countless sideshows evolving at a staggering pace

FAMILY AFFAIR: Mother Donna Kelce (C) gives cookies to her son's Jason Kelce (L) of the Philadelphia Eagles and Travis Kelce (R) of the Kansas City Chiefs during Super Bowl LVII opening night. Pic: Christian Petersen/Getty Images

When the Chinese spy balloon hovered with a mix of menace and mirth across a significant swath of the continental United States last weekend, the unit of measurement of choice was the football field.

The inflated white material carrying surveillance equipment was helpfully described as being 15 football fields x 15 football fields. That seems like an impossible amount of first downs for any offensive unit to crank through.