The rankings make for interesting reading these days.
Among the men's top five, who, other than incoming No. 1 Rafael Nadal, is actually flourishing?
The same can be asked of the women, who are battered by injuries. The lack of dominance at the top should make the Olympics and the U.S. Open even more compelling.
Here's a look at who's hot and who's not heading into the final two major events of the 2008 season.
Rafael Nadal: Nadal has won 32 of his past 33 matches on three types of surfaces, and most know by now that he claimed the French Open and Wimbledon in impressive fashion. Susceptible on hard courts in the past, the 22-year-old cruised to the Toronto Masters title and earned the No. 1 ranking last week in Cincinnati, reaching the semifinals before losing to third-ranked Novak Djokovic. Djokovic blew Nadal off the court in the opening set, although fatigue might have had something to do with it.
Nadal is human, after all.
Proving her appearance in the French Open final was no fluke, Marat Safin's little sister has gone 27-3 in her past 30 encounters, punctuated by winning the East West Bank Classic in Los Angeles and Rogers Cup in Montreal back to back, crushing Jankovic in California along the way.
Her fine displays and those injuries to a slew of others mean Safina already has clinched the women's U.S. Open Series crown.
"I used to win a tournament, then lose first round the next week," Safina said. "Now I'm always just taking it one match at a time."
Andy Murray: Murray's first appearance in a Grand Slam quarterfinal, last month at Wimbledon, has given him more confidence -- and motivation.
The Scot with the versatile game and absorbing character knocked off Djokovic for the first time in Toronto, then repeated the feat in Cincinnati to notch his first Masters title. He now is ranked a career-best sixth.
Sure he had an off day on serve, but the way Murray toyed with ace machine Ivo Karlovic in the Cincinnati semifinals was an eye opener -- the towering Croat was broken four times.
The only player in the top five Murray hasn't beaten is Nadal, and he almost toppled the Mallorcan in the Toronto semis.
Gilles Simon: Simon's win over Roger Federer in the second round in Toronto was noteworthy enough. Even though the Swiss had a poor outing -- which is becoming more and more frequent -- the Frenchman hung in there and didn't lose his cool.
Simon -- a popular figure in Toronto due to his humor and honesty, and a resilient baseliner who can change the pace -- went on to reach the semifinals of that tournament to extend his winning streak to nine matches.
A week earlier, he had captured his first hard-court title at the Indianapolis Tennis Championships.
Losing in the second round in Cincinnati to James Blake might have been a blessing in disguise heading into Beijing -- Simon, up to a career-high 13th in the rankings, was running on fumes the final weekend in Toronto.
Ernests Gulbis: Gulbis, the one-man show from Latvia, at least in tennis, gave Nadal a mighty scare in the second round at Wimbledon, taking the opening set and stretching him to four altogether.
The 19-year-old injured his ankle playing soccer post-Wimbledon, perhaps explaining his first-round exit to unpredictable Argentine Jose Acasuso in Toronto, but he made up for it by advancing to the quarterfinals in Cincinnati.
Gulbis, at a career-high 38th, makes for fine viewing. His serve and forehand are awesome, yet both can go off, leading to some intriguing-looking mishits.
Roger Federer: After his losses to Simon and Karlovic, Federer said he was glad they didn't come at the Olympics or the U.S. Open.
But the losses were hardly the best preparation for Beijing, mind you.
Federer hasn't won a Grand Slam or Masters Series title this season, and alarmingly, his only appearances in Masters Series finals in 2008 have come on clay.
A year ago, there was little chance of Federer squandering a pair of break leads to Simon in the third set. Federer had won eight of nine tiebreakers versus Karlovic prior to losing two to him in Cincinnati.
Maybe carrying Switzerland's flag during the opening ceremonies in Beijing, on his 27th birthday, will give him a boost.
The speedy Russian and world No. 4 has shown little of the form that earned him the Sony Ericsson title in April, going 3-4 in his past seven meaningful matches. (He defeated just one player in the top 80 in claiming a small clay-court title in Poland immediately following the French Open.)
The Serbs: Call Djokovic lukewarm.
Less than 24 hours after an impressive, and less than physically taxing, victory over Nadal in Cincy, Djokovic looked like a completely different player versus Murray.
In the first set alone, he made 31 unforced errors and showed his frustration by tossing his racket and throwing his hands in the air after missing returns.
Also in the opening set, Murray won almost 80 percent of points behind his second serve. Djokovic was broken twice in the second set and routinely pressured on serve in the first.
"I wasn't really happy with the way I played," said Djokovic, who faced 12 break points against Italian Simone Bolelli in his Cincinnati opener.
Once the hottest player around, Djokovic lost in the second round at Wimbledon and earlier than anticipated in Toronto.
His glamorous female compatriots, Ivanovic and Jankovic, are downright struggling, and the injuries haven't helped. (With Maria Sharapova's bum shoulder and the Williams sisters' ailing knees, which of the women's elite aren't hurting?)
Ivanovic, mentally drained in the wake of her maiden Grand Slam title at the French Open, exited in the third round at Wimbledon and third round in Montreal, hampered by an inflamed thumb.
Jankovic, despite catapulting to the world No. 1 position, was a quarterfinal loser in Quebec and is still recovering from a knee injury sustained at the All England Club.
Ravi Ubha is a frequent contributor to ESPN.com.