This Dr. Ivo is no one-trick pony

WIMBLEDON, England -- With long, effortless strides, Ivo Karlovic eased into the main interview room at the All England Club on Friday after beating Jo-Wilfried Tsonga.

Uncomfortable speaking amid big crowds -- he stutters slightly, though he has improved immensely in recent years -- he uncorked this gem upon being told Tsonga essentially said he had nothing but a serve.

"If I can win with only one shot, I'm -- I don't know -- a genius, so I like it," the 6-foot-10 Croat retorted.

To say that Tsonga, an exciting and excitable Frenchman, was the crowd favorite is redundant. Almost anybody who battles Karlovic, and his signature robotic style and ice-cold demeanor, is the crowd favorite.

A certain Roger Federer won't be the exception when the pair meets for the 10th time in Wednesday's much-anticipated quarterfinals. At least the confident Swiss -- seemingly unstoppable this Wimbledon fortnight thanks to the absence of nemesis Rafael Nadal -- paid Karlovic a little respect.

Karlovic, 30, a first-time Grand Slam quarterfinalist, is on pace to finish in the top 25 for a third straight season. The volley, fitness and forehand have improved. And even though it's still a work in progress, Karlovic's latest tool is a drive backhand.

He was nowhere as good when he upset then-defending champion Lleyton Hewitt at Wimbledon six years ago.

"He's become an excellent player," Federer said Monday after a methodical win against baseline-bashing Swede Robin Soderling. "Not only his serve. He's got to have something more, otherwise he wouldn't be ranked where he is, and he wouldn't be beating all those good players."

Of course, the serve is the undeniable weapon.

The right-hander leads the tournament with 137 aces (an average of roughly 35 per match), and hasn't been broken. The lone four break points he faced surfaced in one game of his first-round victory over unheralded Slovak Lukas Lacko. Strangely enough, Karlovic, whose game lends itself to grass, lost his previous four encounters at Wimbledon.

Federer, though, has Karlovic figured out. What a surprise.

Federer is 8-1 in their head-to-head series and has broken him a combined 11 times, manufacturing 40 break points. Karlovic, meanwhile, got his solitary break in 16 attempts at the Paris Masters two years ago.

Tiebreakers figure to be key in this match, and the 14-time Grand Slam champion has a sizable 9-3 edge.

"Federer is Federer," said Cedric Pioline, a former Wimbledon runner-up. "He's more able than the others to pick the few moments where it can make the difference, like the end of a set or a tiebreaker."

So if Karlovic does pull off another monumental upset at Wimbledon, he really would be a genius.

Prediction: Federer in five

Here's a brief look at the other three quarterfinals:

No. 6 Andy Roddick vs. Lleyton Hewitt

Roddick and Hewitt love playing on grass, though both former No. 1s, who won their majors a long time ago, suffered substantial heartache at Wimbledon in recent years.

Roddick's best performance since reaching back-to-back finals in 2004 and '05 is a quarterfinal in 2007. Hewitt, who underwent hip surgery in August, ventured to the semifinals once since winning the whole thing seven years ago.

Roddick has won four straight versus the Aussie battler, although their most recent encounter finished 7-6 (2), 7-6 (4) in the third round of the warm-up AEGON Championships in London two weeks ago.

Roddick saved the only break point.

"I felt like I had the better of him in the actual service games that we were playing," Hewitt said.

Hewitt eliminated grass-court novice Juan Martin Del Potro, the fifth-seeded ball-crusher, in the second round and rallied from two sets down to oust tricky Czech Radek Stepanek in the fourth round. He's sure to get the backing of vocal Aussie fans, too.

Not so good is a thigh injury the world No. 56 suffered against Stepanek.

Roddick looked sharp in beating another Czech, Tomas Berdych, on Monday.

"Lleyton doesn't really have a lot of holes," Roddick said. "He's pretty solid off both sides. You're definitely not going to get on top of him mentally."

Prediction: Roddick in four

No. 4 Novak Djokovic vs. No. 24 Tommy Haas

Mentally fragile after losing to Nadal in an epic on clay at May's Madrid Masters, Djokovic subsequently fell early at the French Open and wobbled at a grass-court tuneup in Halle, Germany. He managed to make the final, only for Haas to down him in three sets.

Coach Marian Vajda wasn't impressed.

"He didn't serve well, he didn't return well, and his mood wasn't really good for that," Vajda said Tuesday after Djokovic finished practicing with Karlovic. "I think this is different motivation. He can't have the same attitude as he did in that match."

A possible Federer-Murray final has made the headlines the first week and a half, which suits Djokovic just fine. On court, the 2008 Aussie Open titlist gained ample confidence by beating U.S. No. 3 Mardy Fish in the third round.

"He's overcome the first two rounds, which is always very dangerous," Vajda said. "As a player who has very big goals, it was very important to roll on. After the Fish match, he got back to his mental strength and back to his habits on grass. I think he's in a good mood and in good shape."

Haas must be in a good mood, too.

At 31, the oft-injured German had never before been in the Wimbledon quarterfinals. He lost to the eventual champion at the Australian Open and French Open, up two sets on Federer in Paris.

Prediction: Djokovic in four

No. 3 Andy Murray vs. Juan Carlos Ferrero

The fans helped an engaging Murray edge past free-swinging Stanislas Wawrinka in a five-set thriller under the roof at Centre Court on Monday.

"When the big points come, especially in long matches when you need a lift sometimes, you need to get the crowd into it," said Britain's huge hope. "I managed to do that well."

Thank goodness for Murray they were there. He looked nervous in the final game, resembling Federer as he attempted to serve out the French Open final.

If he had a bit tougher draw, who knows if Murray would still be around? Luckily for him, he gets another highly winnable tussle, even if Ferrero has now reached two Wimbledon quarterfinals in his past three visits.

Like Roddick and Hewitt, Ferrero held the top spot in the rankings and won a Grand Slam a while back, in Paris six years ago. His dip meant Ferrero, now 70th, needed a wild card to land in the main draw. (Ferrero is the first wild card to reach the quarters since Goran Ivanisevic in 2001; Ivanisevic won the title.)

In their only previous meeting, Murray dismantled the likable Spaniard in the semifinals of the AEGON Championships 6-2, 6-4.

Prediction: Murray in three

Ravi Ubha is a frequent contributor to ESPN.com.