SISTER ACT: Venus (right) and Serena Williams are roommates, doubles partners - and rivals. -- PHOTO: REUTERS

That, remarkably, occurred for five of the six Grand Slams between the 2002 French Open and Wimbledon 2003, but not since.

There is No 7 seed Venus Williams, the four-time champion in the bottom half of the draw. And there is No 6 Serena Williams, the two-time champion in the top half who won all five of those aforementioned Slams. Then there are 14 women who have yet to grace even a single Wimbledon semi-final.

There is no Justine Henin, who retired suddenly in May; no Amelie Mauresmo, who has faded in recent years and lost to Serena; no Maria Sharapova, who went meekly in the second round; no Ana Ivanovic, who went meekly in the third.

To cement the Williams-ness of it all, you had Venus on Saturday throwing in the fastest female serve ever at Wimbledon, 204kmh.

She did it on match point.

It was an ace that went screaming into the corner of Court No 1.

Well, the 14 Others do include Jelena Jankovic, the No3 player in the world but no grass-lover, and they do include a whopping six players from the world's foremost women's tennis incubator, Russia.

'We are Russians,' said Other-14 member Alla Kudryavtseva, who booted out Sharapova. 'We are coming up more and more.'

'I think it's the backgrounds we're coming from,' said Other-14 member Nadia Petrova. 'We really have to work hard for a better living, and I think it's an extra motivation for us.'

'Because we had no support, we grow up strong,' added Other-14 member Svetlana Kuznetsova, the world No4. 'We are very tough.'

The Other 14 include onrushing faces like Hungary's Agnes Szavay, the Czech Republic's Nicole Vaidisova, Poland's Agnieszka Radwanska.

It just does not include the Williamses.

Even at the ancient tennis ages of 28 and 26, Venus and Serena, who grew up in Compton, California, have turned up to define another Wimbledon. Each has won all six sets en route to the fourth round.

Concentration has been evident and pronounced enough that defending champion Venus said: 'I usually don't know the day. Like today, I didn't know it was Saturday. I just knew it was the third round. That's what it's all about.'

They have cohabited as usual. 'We definitely stay together,' Serena said. 'We're roommates. It's pretty cool.'

They have answered questions about Justin Gimelstob and his comments about Anna Kournikova, about the crash-out of the American males.

And mostly, while Sharapova lost to the No 154 player and Ivanovic to No 133, they have embodied a tranquil steadiness.

Now, they are going to rule Court No 2 later today, where Venus will play Alisa Kleybanova. Serena will play fellow-American Bethanie Mattek.

They will return to team up for the third-round doubles, in which Serena said they sometimes spend changeovers talking about 'boys'.

Asked if there is a downside to all this, Venus said: 'I think the downside to having a sister on tour is if she's as good as you are. If she's that good, you have to figure out a way to beat her.'

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