...according to Andy Murray.
Next thing you know it'll turn out some of them have taken performance-enhancing drugs. 
Murray makes match-fixing claim
Andy Murray has told BBC Sport that he believes some tennis matches are being fixed in ATP tournaments - and he says all the players are aware of it.
He told BBC 5live: "It is pretty disappointing for all the players, but everyone knows that it goes on.
"It's difficult to prove if someone has tanked a match or not tried.
"They can try their best until the last couple of games in each set and then make some mistakes, hit a couple of double faults and that is it."
In an investigation for 5live Sport, leading betting companies have expressed concern about the results of several games.
And Murray believes the chance to make extra money is too much for some players to turn down.
He added: "There are some guys who have to come to tournaments every single week and out of their first-round-loser's cheque - about 2,500 euros - they have to pay for their air fares.
"A career lasts probably only 10 or 12 years and you have to make all your money while you're still playing. But it's not really acceptable."
Last month Tim Henman told BBC One's Inside Sport programme he has heard on the grapevine of players being asked to influence the outcome of matches.
"I personally have never experienced it but, listening to the players talking, it seems it goes on," said the former British number one.
And in August, online betting exchange Betfair voided the market on Nikolay Davydenko's match with Martin Vassallo at the Poland Open because of concerns over unusual betting activity.
The ATP Tour launched its own probe as a result.
You can hear Brian Alexander's full report - "Gambling on Tennis - the usual suspects" - in Tuesday's 5live Sport from 7pm.
link
Andy Murray has told BBC Sport that he believes some tennis matches are being fixed in ATP tournaments - and he says all the players are aware of it.
He told BBC 5live: "It is pretty disappointing for all the players, but everyone knows that it goes on.
"It's difficult to prove if someone has tanked a match or not tried.
"They can try their best until the last couple of games in each set and then make some mistakes, hit a couple of double faults and that is it."
In an investigation for 5live Sport, leading betting companies have expressed concern about the results of several games.
And Murray believes the chance to make extra money is too much for some players to turn down.
He added: "There are some guys who have to come to tournaments every single week and out of their first-round-loser's cheque - about 2,500 euros - they have to pay for their air fares.
"A career lasts probably only 10 or 12 years and you have to make all your money while you're still playing. But it's not really acceptable."
Last month Tim Henman told BBC One's Inside Sport programme he has heard on the grapevine of players being asked to influence the outcome of matches.
"I personally have never experienced it but, listening to the players talking, it seems it goes on," said the former British number one.
And in August, online betting exchange Betfair voided the market on Nikolay Davydenko's match with Martin Vassallo at the Poland Open because of concerns over unusual betting activity.
The ATP Tour launched its own probe as a result.
You can hear Brian Alexander's full report - "Gambling on Tennis - the usual suspects" - in Tuesday's 5live Sport from 7pm.
link
Comment