When Serena and Venus Williams face off in the Australian Open final tonight, it will be the first time in more than 100 years of Grand Slam tournament history that the same two women have met in four straight finals.
And younger sister Serena will attempt to complete a "Serena Slam" by winning her fourth consecutive Grand Slam tournament -- defeating Venus in all four finals.
Yet another all-Williams final has left prognosticators examining every factor, no matter how trivial, looking for one that could make a difference in this match.
Certainly, great note was taken of Serena's forehand, which went missing in her three-set semifinal victory over Kim Clijsters, as well as the foot blisters she suffered in the match. Similarly, weight has been assigned to the fact Venus hasn't lost a set at the Australian Open.
Even personality quirks are taken into account. Who is in a good mood? Who isn't? If this sounds trivial, welcome to women's tennis, in which almost every Serena Williams news conference has taken place with a question about clothes or jewelry.
But current form and mood aren't necessarily predictors of Slam success in matches between the sisters. At Wimbledon in 2000, Serena had dropped only 13 games in five matches and was so loose she appeared to be auditioning for a spot on "Saturday Night Live" ... and Venus won their semifinal match.
The "new" Serena has beaten her older sister four consecutive times in straight sets, three in Grand Slam finals in 2002.
This is the first Australian Open final in which they have met. Serena missed last year's event because of an ankle injury, so the sisters have met each other in the last five Grand Slam events both have played (Venus beat Serena in the 2001 U.S. Open final).
The last player to complete a non-calendar-year Grand Slam was Steffi Graf, who completed it here in 1994.
Serena, on a 27-match winning streak at the majors, knows what stands between her and the Serena Slam. "One match and Venus," she said, smiling.
Said Venus: "No matter who it is, I hate to lose. The same with her, maybe even more. Off the court we're sisters again."
On the court too, at least when they play doubles. The sisters won the Australian Open women's doubles title today, defeating Virginia Ruano Pascual of Spain and Paola Suarez of Argentina, 4-6, 6-4, 6-3.
The gap between Venus, 22, and Serena, 21, and other players might not be the Grand Canyon, but Serena is increasingly annoyed by questions about it. Clijsters, who squandered a 5-1 third-set lead and two match points in their semifinal, shares the sentiment.
"We were actually joking about it yesterday in the locker room after our matches," Clijsters said. "She goes, 'Oh, I'm so sick of all these questions.' I said, 'Well, so am I. Why don't we boycott it all?' "
Serena and Venus have four Grand Slam championships apiece. Overall, the rivalry stands even at 5-5.