Sunday, July 08, 2007

Earlier today, tennis great Roger Federer won his fifth straight Wimbledon men's singles title, defeating Rafael Nadal in five sets.

With the win, Federer tied Bjorn Borg for the modern record of five consecutive men's singles titles; Borg was in attendance to witness the match. The all-time record is six, held by William Renshaw (1881-1886).

Whereas the five straight titles might be viewed as a "macro" streak, Federer also came up with a key "micro" streak in the fifth set to transform a tight situation in which the momentum seemed to be going against him into a set (and match) that he won going away. As NBC announcer Ted Robinson noted, Federer was able to "flip the switch" to raise his game to a higher intensity.

Specifically, serving at 2-2 in the fifth set, Federer trailed 15-40. He then hit two service winners (balls that Nadal was able to get a racquet on, but not send back over the net in fair territory) to erase the break points, and went on to win the next two points (four in a row, all told) to hold serve for 3-2.

Federer then broke Nadal -- for only the second time in the match -- by winning four out of five points. Federer then held at love to increase his lead to 5-2. Thus, during this stretch, Federer won 12 out of 13 points!

Federer then won again on Nadal's serve, in a lengthy game that went to deuce a few times, to prevail 6-2 in the fifth.

Tennis is one of the few sports in which an academic statistical study has found evidence of streakiness (non-independence) of winning points. For further information, see the following article, available via Franc Klaassen's faculty webpage.

Klaassen, F.J.G.M. & Magnus, J.R. (2001). Are points in tennis independent and identically distributed? Evidence from a dynamic binary panel data model. Journal of the American Statistical Association, 96, 500-509.

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