USFL Kickoff: Fox Sports, NBC Sports Aim To Revolutionize Football
USFL to eliminate chains, measure first downs with chip in ball
Matthew Berry's Love/Hate for Week 6 of the Fantasy Football
Break the Chain: The USFL's Virtual 1st Down Measurements Are Working
Why the NFL Still Uses Chains to Measure First Downs
USFL will eliminate 1st Down Chain, use technology
USFL announces technological innovations for games, including new
Why the NFL Still Uses Chains to Measure First Downs
Winners and Losers of the NFL's Divisional Round - The Ringer
American football - Wikipedia