James Blake has experienced Roger Federer's brilliance as both a competitor and commentator.

The 17-time Grand Slam champion beat Blake in 10 of their 11 meetings, including 2006 finals at Indian Wells and the Tennis Masters Cup.

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Federer has contested the last two Grand Slam finals and is six weeks away from playing his record-extending 65th consecutive Grand Slam tournament. He has outlasted former top-ranked rivals Andy Roddick, Juan Carlos Ferrero, Marat Safin and the soon-to-be retired Lleyton Hewitt.

The 35-year-old Blake believes there is a secret to the 34-year-old Swiss' success: Federer is a freak because he diligently trains for both tennis and injury-prevention.

“He’s a freak case in many ways,” Blake told The Telegraph's Oliver Brown before his appearance at the Champions Tennis at Royal Albert Hall. “It is underrated that he is just never injured, because he is so well prepared. Some injuries, as I can appreciate, are plain bad luck: you can roll an ankle, slam your finger in a car door. Part of his greatness is his longevity.”

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