We've all become used to the idea that retirement can be a temporary state for top athletes. They never seem embarrassed about changing their minds, no matter how many tributes and special parting gifts they receive or how many naysayers cast doubt on the wisdom of a comeback.
Yet the news that Martina Hingis will return to the WTA Tour next season -- probably at or just before the Australian Open -- deserves to be regarded a little differently. There's nothing to compare it to in tennis, and not much in other sports either.
Hingis excelled young, taking over the No. 1 ranking at age 16 in 1997 and holding it for an astounding 209 of the next 247 weeks. She retired young and gimpy in 2002 and will come back after three seasons away, still not terribly old at 25. Her ankles may be as dicey as a thoroughbred's, but her legs and mind have had what could be a beneficial siesta.
"In the last three years, I think I've gained some confidence in my life outside tennis," she told reporters in a conference call. "I still so much love the game and enjoy it, that's why I want to come back and have the challenge. But really, there's worse things in the world than losing a tennis match."
She will reenter a competitive landscape featuring mostly familiar names and familiar games, with a couple of notable exceptions. The Williams sisters' stars were still ascendant when Hingis was forced out of the sport, and the Russian presence was not as evident. Hingis said she relishes the thought of testing herself against No. 4 Maria Sharapova, whom she last hit against when Sharapova was 12.
Hingis played World Team Tennis this past summer in what now appears to have been a low-pressure way to dip a toe into competition. However, her close observation of WTA goings-on, and some self-evaluation through practice sessions with top players such as Belgium's Justine Henin-Hardenne, might have played just as much, if not more, of a role in her willingness to plunge back in.
"I'm really not that far off," Hingis said. "You have to be hungry, you have to want it and that's why I take the responsibility and make this decision. The same girls I used to play against are still at the top."
A few other women have enjoyed some post-sabbatical success in recent years, but none of them really provides a gauge for what we might expect from Hingis.
Not Martina Navratilova, for whom Hingis was named. The Grande Dame has collected 10 doubles titles and two Grand Slam championships in mixed doubles since her reentry in 2000 after three full seasons off. But Navratilova is 24 years older than Hingis, and although she has played the occasional singles match (the first time literally on a bet), she's never made any pretense of being able to keep up with the WTA's top singles players.
Not Jennifer Capriati, who swatted her way to the No. 1 ranking after 15 months off and some fitness and attitude adjustments -- neither of which were an issue for Hingis until her ankles started giving out and required surgery. And you can't compare Hingis' reluctant farewell and cautiously enthusiastic return with Monica Seles' traumatic exit after being stabbed by a deranged fan in April 1993, followed by a dramatic and emotional return to play.
Hingis is addressing this move like a professional who hopes for the best and is secure enough in her legacy to risk the worst. Normally outspoken and occasionally given to the impulsive, she managed to keep her plans under wraps until the eve of her announcement. In interviews throughout the summer and fall, including one with ESPN.com in late October, Hingis sounded wistful but firm about staying on the sidelines.
"I have to be realistic," she said then. "The top 10 is a different story [than World Team Tennis]. I don't think I could handle that." Her challenges, she said at the time, would come from competing in equestrian events and conquering the black diamond slopes around St. Moritz.
She's trading that in for something that will test her physique and, perhaps even more so, her psyche.
Hingis will have to withstand her opponents' best shots. But she'll also be competing against the indelible image of Hingis Past, the cheery, confident cat burglar whose finesse and court vision neutralized more powerful rivals. That should be an interesting matchup.
The Hingis announcement overshadowed the news that John McEnroe will team up with Sweden's Jonas Bjorkman to play his first ATP-level match since 1992 at the SAP Open in San Jose, Calif., in February. A couple factors could boost McEnroe's ability to hold his own after the long layoff: Bjorkman isn't just any partner, having finished the season ranked No. 3 in the world.
The pair will be playing under the ATP's new match-shrinking scoring rules, in which a tie break (to 10 points, with a two-point gap to win) will replace a third set. An avid doubles player who won 77 titles -- including 17 Grand Slams -- in his career, McEnroe said he wants to boost support for the game, which has been a bone of contention between the top doubles tandems and the ATP.
Freelance writer Bonnie DeSimone is a frequent contributor to ESPN.com.