On the Probability of Winning a Football Game

Abstract Based on the results of the 1981, 1983, and 1984 National Football League seasons, the distribution of the margin of victory over the point spread (defined as the number of points scored by the favorite minus the number of points scored by the underdog minus the point spread) is not significantly different from the normal distribution with mean zero and standard deviation slightly less than fourteen points. The probability that a team favored by p points wins the game can be computed from a table of the standard normal distribution. This result is applied to estimate the probability distribution of the number of games won by a team. A simulation is used to estimate the probability that a team qualifies for the championship playoffs.