Cape Town - The lyrics of the hit parade song "Ups and Downs" would seem ideally suited in comparing the fortunes of premier South African tennis players Raven Klaasen and Kevin Anderson following Wimbledon's illustrious Grand Slam event over the past two weeks.
In a nutshell, after reaching the semi-finals with American partner Rajeev Ram, Klaasen's world ranking is set to rise from 16th to an impressive career-best 10th or 11th this week, with Anderson's woes continuing as a result of a first-round singles defeat against 116th-ranked Dennis Istomin and his world ranking sliding downward from 25th to 31st.
In addition, in the race for one of the prestige eight places in the ATP's year-end World Finals in London, Klaasen and Ram have zoomed into fifth position from nine at the start of Wimbledon, while Anderson is right out of the reckoning having plummeted to 140th position.
It is a storybook rise to prominence for the 33-year-old, King William's Town-born Klaasen, who is now considered among the best doubles players in the world after deciding to concentrate on this format a mere four years ago after achieving a singles ranking of no more than 208th in the world.
"I sat down at the time and took stock of the situation," says Klaasen, "coming to terms with the fact that at 29 years of age I was not likely to make the breakthrough into the top echelon of world singles players.
"At the same time my speed ‘round the court, volleying ability, penchant for hard work and continual striving to improve my game were ingredients that could lift me up in doubles, so I took the calculated decision to devote myself almost entirely to this format of tennis."
It began to pay conspicuous dividends two years ago when Klaasen reached his first and still only Grand Slam doubles final in the Australian Open along with American partner at the time, Eric Butorac.
And helping him raise his level to new heights - as emphasised by the straight-set quarter-final win at Wimbledon with Ram over long-time former No 1 world doubles combination of Bob and Mike Bryan - has been the addition of former South African doubles star Jeff Coetzee to Klaasen's coaching staff.
In contrast, after suffering in turn from shoulder, knee and ankle problems, Anderson has experienced what can appropriately be described as a nightmare tennis year, having won only five ATP games and no more than two in any one tournament after starting the year ranked 12th in the world.
Anderson proclaimed in the warm-up to Wimbledon that he was now physically fully fit and in good shape for the first time in the year.
But psychological scars following a string of poor results can often be more difficult to eradicate as Anderson sets off to his present home base in the United States, where he has achieved some of his best results in the past.
And completing the circle of contrast between Anderson and Klaasen is the fact that Klaasen will be a key factor in South Africa's Euro-Africa Group Two tie against Lithuania in Lithuania at the end of the week.
No one had realistically expected Anderson to end his five-year, self-imposed exile from the Davis Cup on this occasion.