Simpson's paradox

One hope for the Murray-Federer quarter-final in Melbourne is that Federer will be a victim of Simpson's paradox ie he'll win more points than Murray but still lose the match. Dr Ryan Rodenberg of Florida State University reckons Federer has only a 14% success rate in winning those matches where he scored fewer points than his opponent.
An example of this paradox in relation to tennis was the longest ever match: John Isner vs Nicolas Mahut in the Wimbledon Men's Singles tournament in 2010. After playing for 11 hours and 5 minutes over three days, Isner won 6-4, 3-6, 6-7, 7-6 and 70-68. Over the course of the match, Mahut won 24 points more than his opponent and so one might have expected him to win by a set.