Momentum and the Gambler's Fallacy

If you’re watching the Super Bowl today, here’s something to look for. When a big break and masterful execution result in newfound confidence, a team or player often experiences a change in their energy and positivity. 

Good teams and players seize on this good fortune and work to execute even more precisely. When more good things start to happen, players and spectators begin to sense a shift in momentum. 

With each successive play, this newfound success turns into a self-reinforcing cycle. The team or player experiences a surge of energy and takes more steps forward. The momentum of the contest now shifts to one side. 

Everyone on the field and in the stands can feel it, even though they can’t reach out and touch it. Momentum is real. If uninterrupted by the other team or competitors, this spirited force can take over a game and change the outcome in a flash. 

Most statistical experts will tell you momentum isn’t real and serves as just another example of the gambler’s fallacy. Believing a specific event is more likely given the previous series of events is how gamblers lose their shirts. Experts will tell you that, unless an event is identical to the last one, past results have no bearing on future occurrences. This is true even with successive plays or shots. It’s foolhardy to believe otherwise. 

Yet, we frequently witness momentum with our own eyes. The hot-handed tennis player who gobbles up points in succession. The basketball shooter who is on fire and hits five jump shots in a row. The football team on its heels from several mistakes that falls apart. The golfer that strings together successive birdies. The baseball player with the hot bat that goes four-for-four. 

Are we just hardwired to see patterns even when they don’t exist, as many experts claim? 

Data scientist Paul Roebber at the University of Wisconsin-Milwaukee doesn’t think so. Roebber defines momentum as an increase in success over a span of three series. Think serves, golf holes, at-bats, football plays, and so on. 

The key for his analysis was to consider the game score at any point in time and the point spread or advantage one team or player had over the other. After analyzing 10 years of every play in the NFL, Roebber found the chances of winning go way up when a team has more momentum, especially later in a game. Momentum doesn’t just increase a team’s odds. It provides an avalanche of energy that is overwhelmingly advantageous. Teams that win have as much as 15 percent more of these momentum streaks than teams that lose. 

Because momentum is self-reinforcing, the best teams attempt to harness it by keeping any streak of good outcomes alive. When they feel momentum, the players and coaches talk each other up, encourage focus, and execute with more intensity. They know momentum is real and they cling to it whenever they can. They also know all too well that momentum is fragile and can shift back to the other team just as quickly. 

Watch for spans of momentum (three or more successive plays with outcomes highly in a team’s favor) today and see if you can predict a difference in the game. The team that stacks these hot streaks together will likely be the winner. But you could feel that already.