So let's just look at this year's world rankings for the 100 metres.
Top, with 9.75 seconds, Tyson Gay. Who has just admitted failing a doping test. And reported to be among five Jamaican athletes to have failed a test is the man who stands third in the listings with 9.88, former world 100m record holder Asafa Powell.
And who's fourth? Well, that's Justin Gatlin, the United States former Olympic champion who is now back in the sport having served two doping suspensions...but let's not worry about him for now. There's enough to worry about, as far as world athletics is concerned, with today's shocking news concerning the three men above him.
Reports have indicated that one of the other three Jamaican athletes to have failed a test is Sherone Simpson, the 2008 Olympic 100m silver medallist.
It is hard to think of a harsher blow for the sport.
Actually no, it isn't so hard. Similar news concerning the man currently sixth in the 100m listings, Usain Bolt, would be harsher. Almost terminally harsh.
There is no suggestion Bolt has ever been involved in any doping abuse. But it is hardly an easy state of affairs when the man who stands clear as the sport's great modern icon has a growing number of fellow Jamaican athletes who have run afoul of the anti-doping authorities in recent times.
Yohan Blake, Bolt's younger training partner under his coach Glen Mills, served a three-month suspension in 2009 for taking a banned stimulant.
In 2011, sprinter Steve Mullings was banned for life for a second doping offence. He had been training alongside Gay in Clermont, Florida under coach Lance Brauman.
In between winning the Olympic 100m titles at Beijing and London, Shelly-Ann Fraser-Pryce, coached by Stephen Francis, had to serve a three-month ban for taking a banned painkiller following dental treatment.
Earlier this year, double Olympic 200m champion Veronica Campbell-Brown, who is also based in Clermont, Florida and worked with the Brauman training group until 2009, was found to have taken a banned diuretic and now faces a suspension.
Now we discover another five reported Jamaican wrongdoers, including, reportedly, Olympic 2008 100m silver medallist Simpson and the man whose world record Bolt broke shortly before the Beijing Games, Powell.
Both Gay and Powell have been part of the world sprinting landscape for the best part of a decade. The American made his big international debut at the 2005 World Championships, finishing fourth in the 200m. His fall from grace is all the more inexplicable for his previous hard-line stance on doping – he was one of the first Olympic athletes to volunteer for a US Anti-Doping Agency programme that requires regular testing of urine and blood samples.
Powell was part of the silver-medal winning sprint quartet at the 2002 Commonwealth Games in Manchester and has been a consistently high performer despite failing to claim significant individual championship titles. By October of last year, Powell had recorded 88 legal sub-10sec 100m runs, the highest number achieved.
As men, Powell – who is coached by Stephen Francis in Kingston – and Gay – who has been coached by Brauman and former top US sprinter Jon Drummond – have a quiet demeanour in common, but while Powell is a relaxed and jokey character, Gay always presents as rather nervous and brittle.
Gay's personal website betrayed no hint of concern tonight – featuring as it did his latest Facebook posting, congratulating Andy Murray on his Wimbledon victory – "he showed crazy speed on that court in the final".
The crazy speed shown by Gay this season – he also topped the 200m world listings with 19.74sec until Bolt knocked 0.01sec off that time at the Paris Diamond League meeting – has built expectation for the forthcoming World Championships in Moscow.
After conclusive victories in the US trials over 100 and 200m, Gay appeared ready to put in a serious challenge for the world titles he won in Berlin in 2009 but has since seen secured by either Bolt or his Jamaican training partner Yohan Blake, who took advantage of Bolt's disqualification for a false start to win the 2011 100m title.
Now the sport is robbed of that excitement in Moscow.
News of the kind which has just broken leaves followers of athletics in an unhappily familiar state of ambivalence. Of course, it raises the big question that stems from all high-profile doping positives: can we now believe what we are seeing?
It is a mental process with which all followers of the Tour de France currently in progress will be familiar in the light of the blizzard of recent doping revelations centring on the now discredited seven-time champion Lance Armstrong.
There is, too, another familiar question. Is this bad news actually good news in the long term? And is no news bad news?
The fact that the big guys go down under doping bans shows that someone is not afraid to test them and punish them.
Twenty-five years ago, after the seismic sporting shock of Ben Johnson's disqualification for doping after winning the Olympic 100m title in a world record of 9.79sec, the then President of the International Olympic Committee, Juan Antonio Samaranch, insisted: "This is not a disaster. For it shows the IOC is very serious, and that we are winning the battle for a clean Games. The gap between our aims and those who are cheating is narrowing."
Athletics, certainly, is a lot wiser and more active over cheating than it ever was. Which is why, ultimately, today's bad news has to be seen as good news for all the thousands of track and field competitors who do not take the wrong road to results.
Mike Rowbottom, one of Britain's most talented sportswriters, covered the London 2012 Olympics and Paralympics as chief feature writer for insidethegames, having covered the previous five summer Games, and four winter Games, for The Independent. He has worked for the Daily Mail, The Times, The Observer, The Sunday Correspondent and The Guardian.