Most players are bigger and stronger - particularly offensive and defensive linemen, whose size and weight surpass the average man's. Competition for roster spots is fierce, with fewer than 1 percent of all college football players earning a roster post at the game’s highest level. Today, only football’s elite players get to the NFL, and they are very well-compensated: the average contract at the start of the 2017 season was $2.25 million. The game and the players changed over time as the rules changed, and as the league became more competitive, popular and prosperous. Their pay made them “professional” by definition, but with a laxity to the term that would not apply today. It was common for players to “job in” for weekend contests, which didn’t allow for practice time with their teams. Their lives didn’t revolve around the game. Physically, players were bigger, heavier and stronger than the average man, but not astronomically so. Meager pay and a sport struggling for popularity meant players worked other jobs and the league struggled to attract talent. Playing rules prohibited most substitutions, so they played both offensive and defensive positions, on every down.

Nfl play by play