First Quarter (or Nadal's Quarter)
Obviously Nadal has to be the favorite to make it to the quarters, along with Verdasco, Nalbandian, and Ferrer. I wouldn't be surprised if Gulbis made it far as well, and I'd love to see him play Nadal in the quarterfinals.
Most interesting first round match:
Gulbis vs. Chardy or Ferrer vs. Dolgopolov.
Most interesting possible second round match:
Nadal vs. Istomin (and really, Nadal should kill him...but not many interesting second round matches to choose from so if you're going to watch someone you might as well watch Rafa)
Most interesting possible third round match:
Nalbandian vs. Verdasco
Most interesting possible round of 16 match:
Ferrer vs. Nalbandian (or Verdasco)
Quarterfinals prediction:
Nadal vs. Nalbandian
Second Quarter (or Murray's Quarter)
In my opinion, Murray and Berdych are the clear favorites to reach the quarterfinals in this section. Querrey and Wawrinka are capable of upsets but they'd have to beat Murray to get to the quarters, and I can't see that happening. Berdych could have some trouble with Almagro, Youzhny, or Isner (but that's only if Isner plays and if he's healthy, which at this point seems like it won't be happening), however, I'd be surprised if Berdych doesn't make it to the quarters.
Most interesting first round match:
Berdych vs. Llodra or Youzhny vs. Golubev
Most interesting possible second round match:
Stepanek vs. Robredo (I tried to find a better one, really I did)
Most interesting possible third round match:
Murray vs. Wawrinka or Almagro vs. Querrey
Most interesting possible round of 16 match:
Murray vs. Querrey or Youzhny vs. Berdych
Quarterfinals prediction:
Murray vs. Berdych
