One of the great things about tennis is that there's always the possibility of an upset.
Crowds love it when an underdog plays the match of their lives and topples a more highly rated player.
Having been to several Wimbledon tournaments as well as a French Open, I have experienced that thrill as a spectator. But were those upsets I witnessed for real, or was it all a fix? Had we all been duped?
News broke yesterday that secret files allegedly containing evidence of widespread match fixing at the top levels of world tennis have been revealed.
Dozens of top players are suspected to have been involved in match fixing, with some suspected to have deliberately lost matches.
It is alleged that some of those players are taking part in this year's Australian Open, which got underway yesterday.
We probably shouldn't have been surprised by the news, given the increasing amounts of money tied up in online sports gambling.
Cricket has been rocked over the years by match fixing scandals, with New Zealanders among those caught up. Watching cricket has never been quite the same. Now it's tennis' turn.
The allegations have cast a shadow over the Melbourne tournament for the spectators but also for the players.
From now on a top player having a bad day - making more unforced errors than usual, serving a double fault on a crucial point, missing an easy smash - may find themselves under a bit more scrutiny than usual.
As sports fans, we will be hoping these are genuine mistakes. But thanks to yesterday's revelations from now on there may always be a wee smidgen of doubt.