Education: Attended tennis training centers in Switzerland.Tennis player; won junior Wimbledon singles and doubles and the Orange Bowl (Miami, Florida) title, 1998; ranked No.

Jim Courier was the only player worse than 50-50 in such matches, with a non-alarming 11-15 record. First, given Federer’s decade-plus time as one of the top ranked players in the world, it is possible that his opponents chose to adopt a high-risk, yet upset-friendly playing style when on the other side of the net as an underdog.

Knowing that their normal playing strategy would be unsuccessful against the near-unbeatable Federer, his opponents may have decided to select the optimal strategy for an upset, one described by Brian Skinner in a 2011 When facing a heavily-favored opponent, an underdog must be willing to assume greater-than-average risk.

Simpson’s Paradox is a statistical quirk where seemingly correlated variables are reversed when combined.

The application to tennis is nuanced: In tennis, a derivative of Simpson’s Paradox is seen in the small percentage of matches where players win more individual points than their opponent, but lose the overall match.

This result surprised us, as it differed wildly from other players who had similarly won multiple Grand Slam singles titles.

Andre Agassi, Rafael Nadal, Pete Sampras, Sergi Bruguera, Marat Safin, Lleyton Hewitt, Yevgeny Kafelnikov, and Gustavo Kuerten were all .500 or better in Simpson’s Paradox matches. There are two non-mutually exclusive explanations for Federer’s curious results.

At one end of the spectrum was American player John Isner.

At 6’10,” Isner unleashes one of the most intimidating serves in tennis history.

A review of Isner’s career record in two dozen similar matches—that is, matches in which the winner won fewer points than the loser—revealed an impressive 19-5 record.