London, Jul 2: Russia's Elena Dementieva and Dinara Safina have been tasked with solving the riddle that has so far proved way beyond the abilities of anyone else in the women's draw at Wimbledon this year.
How do you stop the Williams sisters? As Venus and Serena inexorably cruise towards a fourth all-Williams final, world number one Safina and Dementieva are hoping to break their formidable stride and secure the first all-Russian clash instead.
And the Russians meant business as they took to the All England Club's practice courts on Wednesday to prepare for combat.
Hidden away on one of the back courts, Safina -- who faces a first Wimbledon semi-final against Venus -- may have been out of sight of her fans, but she was not out of earshot as she noisily powered shots back at her coach from the baseline.
Wearing a bright blue top and black hot pants, the top seed spent over an hour working on her game in the midday heat before doing some fitness training, side-stepping along the tram lines as she threw a basketball back and forth with her coach.
Despite being the world number one, the Russian is expected to be a mere stepping stone towards another final for third seed Venus, who is chasing a sixth Wimbledon title and has not dropped a set here since the 2007 third round.
But the 23-year-old won't go down without a fight. "I have nothing to lose...I played her in Rome and I beat her in Rome," she said.
"I know her weapons. I have my weapons. So I just want to go out there, play my best, and let's see."
FOCUS ON FITNESS
Two courts along from Safina, fourth seed Dementieva, who blamed her lack of fitness for her third-round exit from the French Open and said it had been her focus in preparing for Wimbledon, spent a long time exercising before picking up her racket.
The Olympic champion, wearing black shorts and a white t-shirt and visor, ran laps around the court forwards, backwards and sideways before sprinting, hopping, jumping and doing squats as she worked on her physical condition in blazing sunshine.
Eventually getting down to some tennis the world number four, who faces Serena in the first match on Centre Court on Thursday, was quieter than her compatriot as she practised, only letting out a shriek when a volleyed ball hit her thumb.
With double faults a concern for the Russians in their quarter-final ties -- Dementieva averaged a double fault per service game and Safina racked up 15 in her three-set win over Sabine Lisicki -- both also took time to work on their serves.
In contrast to their opponents, the Williams sisters warmed up in the spotlight, motoring to a 6-2, 7-5 quarter-final doubles win over Anna-Lena Groenefeld and Vania King on Court Two.
Although serial semi-finalist Dementieva has won four of her last five encounters with Serena, men's second seed Roger Federer put his money on an all-Williams final.
"It seems when they're playing well that there's not much of a chance for the other girls," he said of the sisters after his quarter-final win against Croatian Ivo Karlovic on Wednesday.
"It's been quite incredible what Venus has been able to do here at Wimbledon...just being so consistent for so many years.
"Serena obviously having won the career Grand Slam already has always been one of the biggest contenders for any major in the last few years," the Swiss added.