After a lengthy wait while the numbers were crunched, JMdP celebrates making it to the semis. LONDON, ENGLAND - NOVEMBER 26: Juan Martin Del Potro of Argentina celebrates going through to the semi-final after he won his match during the men's singles round robin match against Roger Federer of Switzerland during the Barclays ATP World Tour Finals at the O2 Arena on November 26, 2009 in London, England. (Photo by Julian Finney/Getty Images)

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With three players finishing round robin play Group B was decided by the first tiebreaking criteria, number of sets won and lost.  Soderling (5-2) and Davydenko (5-3) barely edged out Djokovic (4-3) for the two semifinal spots, despite being the two lowest ranked players in their group.

But as close as Group B was, Group A was even closer.  In a group which saw all six matches played last three sets, Roger Federer, Andy Murray, and Juan Martin del Potro all had won two matches, and each had a 5-4 record in terms of sets won and lost.

And it wasn't clear cut after that, going into the second tiebreaking measure. The three had incredibly close games won and loss differentials, which wound up deciding the two semifinalists to emerge from the three-way knot.  Federer had a games record of 44-40, which was good enough to be first.  del Potro (45-43) barely snuck by Murray (44-43) for the final semifinal berth from Group A, despite Murray beating del Potro in their head to head match-up.  The Brits, understandably, have been left with a bad taste in their mouths about the whole thing.

Once it comes down to the second tiebreaking category, like it did in this instance, it's bound to be fairly arbitrary.  A quick non-tennis aside on the topic of tie breaking criteria--how is away goals a valid tiebreak for these World Cup qualifying matches? If, for example, Croatia and Poland tie 0-0 in Warsaw, then tie 1-1 in Kiev, Poland gets through? Completely arbitrary, even if home field advantage is a recognized intangible.  

Last (and least), it was a bad week for the Spaniards, to be sure. Rafael Nadal and Fernando Verdasco went a combined 0-6 on the week, finishing last in their respective groups.  The two Spaniards were the only winless players in the tournament, with each of the six other competitors winning two matches apiece.  Fernando Verdasco put up three valiant fights in his three matches, all three of which were three-setters (including two of the third set tiebreak variety). Nadal, on the other hand, was totally hapless, not winning so much as a single set during the event.  Sadly, for Nadal, this was a totally foreseeable performance.  He hasn't been the same player in the slightest since Madrid, and he has a long way to go if he wants to come close to defending his Australian Open title.  In the more immediate future, he (and Verdasco) have got to shape up in time for next week's Davis Cup final vs. the rested Czech Republic if Spain wants to avoid what would be a massive upset.

I'm guessing there will be a rematch of this year's US Open final on Sunday in London, though with how well Soderling has been playing, a rematch of the French Open final wouldn't be entirely shocking either.