This year's U.S. Open, which starts Aug. 25, is sure to surprise. The defending men's champion, Rafael Nadal, has withdrawn from the tournament because of a wrist injury. Does Roger Federer, who won five U.S. Open titles in a row from 2004 to 2008, have one last run in him? Will Wimbledon champion Novak Djokovic take his first title since 2011? Will a new player, like Milos Raonic, the 6-ft. 5-in. Canadian big server who's looked strong in the hard-court tune-ups, break through?
On the women's side, Serena Williams is the wildest of wild cards. She's the two-time defending champ and still No. 1 in the world. But she's been strangely inconsistent this season, and the U.S. Open is her first Grand Slam appearance since Wimbledon, site of her bizarre appearance at a doubles match with her sister. The sport is still buzzing from that incident, in which a dazed Williams couldn't serve the ball over the net. It was equal parts strange and scary.
This year's U.S. Open is pretty unpredictable. But if a new academic study, to be published in an upcoming issue of the Journal of Sports Economics, holds serve, this much is guaranteed: the men's players will embarrass themselves more often than their female counterparts.
The study — conducted by economics professors from Deakin University in Melbourne and Sogang University in Seoul — examined line-call challenge data for 331 professional men's matches, and 149 women's matches, from 2006 to 2008. The major finding: as the competition got tighter, men were more likely to screw up. During set tiebreakers, female players were more likely to make the correct challenge call, and men more likely to make an incorrect call. (There's a risk to making a challenge — if the Hawkeye system shows the ump was correct, you lose a challenge and the potential to correct a future call. In the U.S. Open, players are allotted three challenges, plus one extra during the tiebreak, per set.)
What's more, during tiebreaks, 34% of men's challenges are "embarrassing" — defined by the researchers as questioning a correct call when the ball is more than 50 mm off the line. Only 9% of women's challenges are "embarrassing," a statistically significant difference. Men are more likely to make these stupid challenges when the ball is on the other side of the court, which is a riskier call since the net impedes their view. The higher a man's ranking, the more likely he is to make an embarrassing line-call challenge. For women, the opposite holds true: the higher the ranking, the more prudent the decision to challenge a call.
The authors chalk up these gender differences to overconfidence, pride and shame. Men are more prone to cockiness, and think that their perspective is always correct, even when the naked eye can see that a ball is in or out, they say. Men also possess a disproportionate amount of pride. They can't bear to lose, and are more susceptible to making an irrational attempt to reverse an umpire's judgment. "It's an ego thing," says tennis great Martina Navratilova, winner of 18 Grand Slam singles titles.
And if the crowd, and millions watching on television, see them making an embarrassing challenge, men won't feel as much shame as women. They don't see the same downside to screwing up. "Guys just don't care as much about losing challenges," Navratilova tells TIME. "Women are more concerned about being embarrassed."
Or, as the authors of the study put it, "at crucial moments of the match, such as tiebreaks ... male players try to win at all costs, while female players accept losing more gracefully."