PARIS -- Whatever their form, whatever their results, the Williams sisters are still viewed first as a unit and secondly as the dual chalk mark on the wall that any top woman player measures herself against.
One of the most intriguing questions in the sport this season is whether Venus Williams is intent on and capable of measuring up to her former stature. Her enigmatic third-round loss to Jelena Jankovic at the French Open didn't provide much of an answer.
Jankovic arguably has the most forward momentum of any player on the women's tour. Coming into this tournament, she had beaten Venus Williams twice in the last calendar year -- once at Wimbledon and once on clay in Charleston, S.C., in April.
Williams' play has been largely workmanlike since she returned to a more or less full-time competitive schedule earlier this year and won her first event out of the box. She shut herself down from July 2006 until last February to allow her injured wrist to heal, playing two matches in that stretch.
Still, Jankovic made it clear Friday she was seeing double -- staring down both a formidable player and a formidable conjoined reputation.
"Each time you play the Williams sisters, it's really a tough game," the fourth-seeded Serbian said after topping Venus 6-4, 4-6, 6-1 in the third round of the French Open. "You have to be on the top of your level if you want to beat them. They are the best athletes in the women's game."
If that were true, though, would Williams have so obviously run out of steam when it counted? She reeled off the first three games in the second set and defended that beachhead to force Jankovic to go the distance.
"(The third set) went a little faster than I expected," Williams said.
And later, "I just couldn't get my feet where I wanted them."
There's no question Williams still brings considerable presence to her side of the net. She did, after all, just hammer the fastest female serve in history, a 128 mph screamer, on these very grounds the other day. Yet perhaps it's illuminating that the feat seemed to surprise her, as if it were a fluke rather than a sign of renewed strength.
Williams had the eye of the tigress in the second set Friday as she drove Jankovic deep with shot after shot, hammering her forehand side to rob the 22-year-old Serb of one of her better weapons. Jankovic only came to the net eight times all match, though she also converted on all those chances.
But Williams' serve petered out in the third set. Jankovic pounced on it and ran her from side to side, to the raucous approval of her personal rooting section, which may be second-loudest only to James Blake's at the U.S. Open. Since the "J" in "Jelena" is soft, her crew could be dubbed the Yay-Block.
Jankovic didn't ratchet down her respect level afterwards, though.
"Half the balls I hit today I thought was going to be a winner against the other girls, and then against Venus, it is not," Jankovic said. "She gets them, and she makes a winner back. So this is what is really great about the Williams sisters."
There's that corporate reference again.
It's worth recalling that Jankovic's rise to prominence coincided with the Williams siblings' interim fade-out. Last year, Jankovic's first season in the top 20, was the season the sisters dropped into the nether regions of the charts.
Confident and zoned-in as Jankovic may be right now, she's still new at the psychodynamics of playing a star whose position in the sky has shifted lower and closer to the horizon. That might make her ever so slightly vulnerable to the memory of what was instead of what is.
Venus is too smart to believe her own leading-lady PR, but some of her postmortem comments indicate that she's still hoping for success in this comeback season, rather than willing it.
She guessed she might be overtraining on her off days. She described the sensation of losing her grip on the match as that of running out of time, but this is a game without a clock, where endurance and belief are an enormous part of the equation.
"In my experience, when [a shot] goes long, long, long, it's only a matter of time before it goes in, in, in," Williams said.
And later, "I would have liked to have moved forward a little bit more, but it's still early."
Is it? After Friday's match, Williams fielded some inquiries about her fitness and attitude heading into Wimbledon, where her victory two years ago confounded tennis fortune-tellers. She won't play any events between now and the last week of June.
Williams will walk out onto those famous grass courts exuding a legitimate and well-deserved aura of intimidation. It's not something a player can fritter away all at once. But that fine lingering mist may start to evaporate bit by bit as her opponents start living in the present and learning that legends don't win points. Legs do.
Bonnie DeSimone is a freelancer who is covering the French Open for ESPN.com.