Paris ? So much has changed for Serena Williams since the last time she arrived at Roland Garros to play in a French Open.

She has won four straight majors, a self-styled “Serena Slam.” She claimed the No. 1 ranking from her older sister. She sparked talk of an undefeated season and had some wondering whether she might need to pull a Sorenstam and play against men to find a true challenge.

And that’s just on the court. Away from it, too, Williams fully emerged from Venus’ shadow, dabbling in acting and modeling, finding her adult voice.

“The French Open,” Serena Williams said, “was the beginning of the big story.”

When play starts at the French Open Monday, Williams will have a chance to win a fifth straight major title, something last accomplished by Steffi Graf in 1988-89. Williams also could take the second step toward a calendar-year Grand Slam.

Suddenly, however, other players might truly believe that another all-Williams Grand Slam final isn’t such a sure thing. After opening 2003 with 21 straight victories, Serena lost twice in about a month: against Justine Henin-Hardenne in Charleston, S.C., and against Amelie Mauresmo in Rome.

“She can be frustrated,” Henin-Hardenne said after her victory. “I think it’s good for the other players that we can see that.”

Venus, meanwhile, fell to No. 3 in the rankings last month. And May 4, she quit during a match against Mauresmo with a stomach muscle injury.

“Everybody’s playing better these days,” Serena said. “We’ve definitely raised the bar.”

Both statements are true. The list of challengers includes Mauresmo, a semifinalist at Wimbledon and the U.S. Open last year; Henin-Hardenne, the 2001 French Open runner-up; Kim Clijsters, who supplanted Venus at No. 2 and has won the same number of tournament this year as Serena (three); and 2001 champion Jennifer Capriati.

The men’s tournament is far more wide open. Plenty of players could make a strong case that they’ll win, from top-ranked Lleyton Hewitt, to eight-time Grand Slam champion Andre Agassi, to 2002 finalist Juan Carlos Ferrero, to 1998 champ Carlos Moya, to three-time winner Gustavo Kuerten, to fifth-seeded Roger Federer, to any of a number of relatively anonymous players who happen to be particularly adept on red