YES, MOMENTUM REALLY DOES MATTER

Another big play, another first down, and your team is on a roll. The fans go wild! You’re winning this game for sure…

Not so fast, academics have long claimed. Momentum is imaginary, and success doesn’t necessarily lead to continued success.

But UWM Distinguished Professor Paul Roebber has proved the fans right. He used machine learning and 10 years of play-by-play data from NFL regular-season games to show that momentum within a game is real and that it improves a team’s chances of winning.

Roebber trained a neural network – in which the algorithms perform like the connections of neurons in the human brain – to predict a team’s probability of winning through momentum.

Roebber

The model defines momentum as an increase in a team’s “win probability” over the course of at least three changes in ball possession, based on factors such as the down, score and the team’s location on the field.

Both offense and defense contribute to win probability, Roebber says. So positive momentum by one team coexists with negative momentum by the opposing team.

Previous research that failed to establish a correlation between momentum and game outcomes looked primarily at streaks from individual players, not a team’s collective effort.

“The home team might improve its chances of winning through an offensive possession, and then the visitors get the ball,” he says. “And perhaps the home team defense holds their opponents to a three-and-out, which gives the home team possession of the ball in good field position. That would be considered two positive changes in possession, where the home team has improved their chances of winning on both sides of the ball.” – Laura L. Otto