What Is The Definition Of Completion Percentage In Football?1. This is the percentage of passes completed from the number of passes attempted by a football player, usually the quarterback. The completion percentage can be in a game, season, playoffs or career. Examples Of How Completion Percentage Is Used In Commentary1. McNabb had a great day throwing the ball, finishing 35 for 40 for a completion percentage just over 77 percent, with two of the passes going for touchdowns. Sport The Term Is Used