The ball was clearly out . . .

The Associated Press files a report today on the use of instant replay in professional tennis. Some players like it -- Andy Roddick and James Blake, notably -- and some don't -- count Roger Federer in this camp.

Here's Roddick on the system: "I think it's great what they've done with the challenge system," Roddick said. "I think it takes a lot of the question out of it."

Blake: "It humbles the players sometimes. It humbles the officials sometimes. And I think it's great because we're probably both too arrogant at times. The players always think they're right and the umpires always think they're right, and it shows that neither of us are always right."

And here's Federer, arguably the greatest to ever play the game, on challenges: "I think it's nonsense," he said. "Now they can hide even more behind these calls. We would like to be able to rely a little bit on umpires. They tend to now just let us do the work, the tough stuff. They let us get embarrassed, basically."

Personally, I'm all for the instant replay system -- which gives players two challenges per set -- with one caveat. I don't think it should be used in a tournament unless it is available on every court. Otherwise, matches are being played under different conditions, which, I think, erodes the credibility of the tournament.

Still, I think Blake sums it up best: "As long as the fans like it," Blake said, "I say we keep it."