"Serving fast is a combination of hand and racket speed," Tanner says. "But the reason they all serve so fast today is because they are so big. They are all giants of 6ft 4. I'm 6ft, which was about average when I was on tour. Now they keep growing."
Ken Rosewall gives hope to all players over 40. Rosewall is still playing at Wimbledon some 44 years after his first appearance.
He is now 62 and plays in the 45 and over doubles, but still runs around with all the enthusiasm of his youth and hits the ball with superb precision.
Rosewall likes to play at least twice a week if possible and says: "I live near John Newcombe and Tony Roche in Sydney and often knock up with them. Mark Edmondson and Brad Drewett also join us occasionally so we get some very useful practice."
For tennis buffs who want something different, Wimbledon are selling The Ballad of Worple Road written by Max Robertson, who from 1946-1986 reported from the Championships on BBC Radio.
Robertson's work records the history of the All England Club at its former grounds in Worple Road from 1869-1921 - all in verse.
South Africa's Christo Van Rensburg, who has been playing in the men's and mixed doubles at Wimbledon this year, has one other claim to fame - he is a bit of a magician.
"My worst moment was about 10 years ago," he says. "I was in Atlanta chatting to golfer David Frost, his wife and a few other friends and was keen to show what I could do. We were about 20 floors up on a skyscraper balcony and I asked David's wife to lend me her very expensive diamond engagement ring. I intended to make it disappear.
"Unfortunately, it dropped out of my hand before I could palm it, rolled towards the edge of the balcony railings and stopped just three inches short. I would still be paying off the insurance now if it had gone over the edge."Reuse content