But a 1985 study found that basketball players and fans believed "a player's chance of hitting a shot are greater following a hit than following a miss on the previous shot," but neither a statistical analysis of two NBA teams' shooting records nor a controlled experiment with collegiate basketball players backed it up.
One recent study on momentum in professional football looked at more than 500,000 video replays in the NFL and tried to tease apart whether a big play on defense led to the offense moving the ball or scoring. It didn't, according to Aaron William Johnson, a graduate student at the Massachusetts Institute of Technology who submitted a paper to the Sloan Sports Conference in 2012.
"Me and my co authors are big football fans and we wanted to see if there was evidence for it," said Johnson, who is in department of aeronautics and astronautics. "We can't say it doesn't exist, but we couldn't find it."
Johnson and other academics look at something called the momentum chain, a six-step process that transforms a psychological action into a physical change and finally a change in performance and outcome on the field. Johnson noted that the chain often gets a few kinks in a team sport.
"It's a complex chain and when you have 22 players," he said. "There's a lot of places for this to get lost."
In the World Cup, one aspect of momentum appears to hold true. Teams that win their first game are likely to move deeper into the tournament. Since 1998, only 4 of 46 teams that lost their first game have advanced to the round of 16.
Meanwhile, 84.8 percent of teams that won their first game and 58.3 percent of teams that drew their first game advanced, according to the Wall Street Journal. Perhaps that's why the U.S. men's national team, as well as every other World Cup squad, is eager to win right away.