Andy Roddick likes it. Roger Federer doesn't.
Only one thing is clear: The new challenge system for close line calls is changing tennis for players and spectators alike. And it looks like the technology is here to stay as human errors _ and the arguments they spawn _ get shunted to the sidelines.
"I think we're all in favor of it," said Wayne McKewen, the tournament referee for the just-finished Australian Open, which employed the so-called "Hawk-Eye" system for the first time, following in the footsteps of the U.S. Open last September.
"The chair umpires like it. They like to see calls correct. This way we get a definitive answer."
Next year, expect more courts at Melbourne Park to have Hawk-Eye, which costs about US$50,000 per court, not including the large-screen TVs where players and fans alike watch the technology-enhanced replays.
Most players seem to like it, too, with some big exceptions like Federer.
Roddick argued repeatedly with the chair umpire about calls during a match on a court that didn't use the technology.
"He's pretty much the only other person I can vent my frustrations to besides myself," he said. "So unfortunately sometimes they catch the brunt of it."
Roddick then was on his best behavior, with the rest of his matches on Rod Laver Arena, the only court to have the system here so far.
"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."
It certainly has curtailed racket-smashing tantrums over close calls. The only times that famously volatile Marat Safin tossed his racket came because he was mad at the way he was playing.
"You don't need to argue with the chair umpire, go into any sort of histrionics," James Blake said. "Just go about your business. We know we're not getting the short end of the stick three or four times in a row or anything like that, so it maybe keeps guys in the match a little bit better mentally.
"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."
Still, one of the most influential players, Federer, wishes the system would go away, saying it has shifted the onus on correcting calls from the chair umpires to the players.
"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."
There did appear to be fewer overrules by chair umpires of line judges' calls on Rod Laver Arena. And judging by the number of times that Hawk-Eye led to calls being changed, overrules are still needed.
During the tournament's two-week run, players made 122 challenges and got 60 _ 49 percent _ overturned. Ironically, Federer was a beneficiary, making the most challenges, 17, and getting 11 calls changed.
The system uses a minimum of eight cameras _ Melbourne Park used 10 _ and a computer system to chart the path of a ball and where it makes contact with the court. Players get two challenges per set and only lose one if they challenge a call that initially was correct. An additional challenge is added for a tiebreaker.
If there's a fault, it seems to rest more in the challenges. Roddick said they have spawned new strategies.
"Let's say he's serving at 40-love and I'm receiving, you're going to be a lot less likely to challenge a ball than if it's break point," Roddick said.
Players also hesitate to challenge very close calls _ particularly early in a set _ worrying they will run out of challenges when they might need them.
"I think it's better to just play if you're not a 100 percent sure," Kim Clijsters said. "If it's that close... I wouldn't risk it. I'd rather play the point and try to just win the point."
McKewen said players shouldn't worry so much about running out of calls.
"If there's a call where the chair umpire is unsighted, he can call for a challenge," McKewen said.
But there was no such call in Serena Williams' semifinal match against Nicole Vaidisova, who hit a ball close to the line on match point. It was called good, and Williams clearly wanted to challenge but had already used her allotment.
TV replays showed the ball was out. As it turned out, Williams finished off the match two points later.
The likely key to the whole issue is how the fans like it, and the crowds in Rod Laver Arena got into it, frequently urging players "Challenge it!"
"As long as the fans like it, I say we keep it," said Blake, who has been vocal in backing any changes that keep the sport's popularity high.
Andy Roddick likes it. Roger Federer doesn't.