Serena and Venus share single vision of triumph

The Williamses are not only sisters but best friends, doubles partners and flat-mates

We cannot know what scene unfolded this morning in the rented house where Venus Williams, the world No1, and Serena, the younger sister who will officially dethrone her in Monday's rankings regardless of what happens in today's women's singles final, are staying.

We cannot know if the breakfast table banter moved beyond "pass the juice" and "looks like rain again" or whether it was Venus or Serena, or even mom, Oracene, who got the first break of the day by beating the others to the hairdryer.

It is easier to imagine the scene on Thursday evening. For everyone else it was semi-finals day. For Venus, who had beaten Justine Henin, and Serena, who had seen off Amelie Mauresmo, it was the Champions' Ball come early. The Williams sisters, two people, one aim, had already been guaranteed victory.

That is one reason why today's final is so hard to call. Venus has spoken in the past about how a triumph for one is a triumph for the other. They concur that they revel in the other's success. They are best friends, doubles partners, hitting buddies. They live together in Florida, out of choice, not because they have to. Venus was even asked earlier this week what single question she would ask Serena to elicit a hitherto unknown piece of information. She said questions were unnecessary.

"The spectators probably don't know which one to root for," Venus said after losing their last meeting, the final of the French Open last month. "I guess everyone has their favourite player, but when it comes to me and Serena, people see us as the same."

It had been an error-strewn match, won by Serena and endured by the spectators. Venus forecast then, that if they met in the Wimbledon final: "With our style of serving and returning, the grass would really bring the best out of both of us. In a way it will be a bit more fun." We can but hope.

There are key differences between the two. Venus is older, shyer, more academic. She is also taller and quicker. But not quite as close to the epitome of muscled athleticism that is Serena.

Their games are rooted in power. Venus served the fastest ball the women's tour has even seen last year, at 125mph. Serena is not far behind and, in this tournament, has served 37 aces to Venus's 18. The older sister's serve has more variety with placement, Serena's is often more accurate.

In rallies they hammer their groundstrokes from the baseline, although Venus, here, has displayed an increasingly willingness to come to the net. She attributed this to new confidence in her volleys, imbued through playing doubles with her sister. Serena does not come forward nearly as much, but her power from the back of the court is usually adequate to blow opponents away. In her semi-final against Mauresmo, she did not need a single winner at the net.

So how can the pair be separated? Not, for the moment, by talent, because Venus's tiny edge in power is counterbalanced by Serena's superior natural touch. And not, for the moment, by desire. Venus states in her official biographical notes that her "life goal" is to avoid further speeding violations, but winning a hat-trick of Wimbledon titles must be up there. Serena states that the biggest goal in her life is to win Wimbledon, pure and simple. Against whom she does not say, but it is safe to assume that any opponent except Venus would be preferable today.

A fix is a popular theory, after a phone call from their father, Richard, estranged from Oracene and absent this year. But even if you buy the notion that the sister's early Slams were divvied up like Hershey Kisses at a picnic – no firm proof exists and perhaps never will – it is clear they have been encouraged to compete, and brutally.

The American writer L Jon Wertheim recounts in his book, Venus Envy, a practice session when Venus was 13 and Serena was 12. Rick Macci, their coach at the time, tells Wertheim how Richard Williams positioned the sisters six feet apart on opposite sides of the net and ordered them to whack balls directly at each other. "I want you to take her eye out," Macci recalls Williams saying. Venus eventually slammed a ball into Serena's chest. "As Serena tried to hide her tears," Macci said, "Richard nodded approvingly."

That kind of humiliation is never likely to be repeated in public, which leaves the omens as the best prediction tool. Even they are duplicitous. The only other time sisters have met in a Wimbledon final was in 1884 when Maud Watson defeated her elder sister, Lilian. So it could be Serena, the youngest, again. Or Venus because the senior sibling is due a break. Over to you girls. When you've finished your cereal.

Williams V Williams: The Finals

Key Biscayne, Florida 21 March 1999

Venus won 6-1, 4-6, 6-4

Venus, 18, was the defending champion. Serena, 17, had won her previous 16 matches. Venus swept through the opening set. Serena levelled the match, but was broken early in the final set. Although Serena recovered the break for 4-4, Venus made the decisive break in the ninth game. "I'm shaking," Richard Williams, their father, said. "My only hope in watching my babies is that I don't cry."

Grand Slam Cup, Munich 3 October 1999

Serena won 6-1, 3-6, 6-3

Serena blew her older sister away in the first set, winning 12 of the first 13 points. Not one to lie down, Venus hit back as Serena's game suffered, taking the second set 6-3. However Serena again found her feet and claimed victory in the deciding set. Serena said: "I didn't know how it would feel. It's kind of tough to take this win".

United States Open 8 September 2001

Venus won 6-2, 6-4

Plenty of hard-fought rallies, and some breathtaking points, but Serena was not going to deter Venus by committing 36 unforced errors. Venus broke for 3-2 and 5-2 in the first set, a double-fault costing Serena the seventh game. Serena recovered from 0-2 and 2-3 in the second set, but a dreadful service game at 4-4, opening with two double-faults, tilted the balance.

French Open 8 June 2002

Serena won 7-5, 6-3

So error-strewn as to be almost laughable: 13 breaks of serve, eight against Venus, who double-faulted nine times. Both players belted the ball vigorously, but the harder they tried, the worse the match became. Venus was credited with only four winning shots, relying on Serena's 54 errors, while delivering 47 of her own. Serena hit 11 winners, two of them aces.