|Usain Bolt shatters the World 100m record at the Beijing games [GALLO/GETTY]
Twenty years divide two astonishing Olympic 100 metres finals where the world record was not merely broken but shattered.
At the 1988 Seoul Games Canadian Ben Johnson exploded from the blocks to cross the line in 9.79 seconds, four hundredths of a second faster than his own world mark.
This year the Jamaican Usain Bolt clocked 9.69 seconds in Beijing, bettering his old record by three hundredths of a second.
The first race resulted in the biggest drugs scandal to hit the summer games when Johnson tested positive for the steroid stanozolol.
The sport of track and field, and in particular the 100 metres, has struggled for credibility since.
Just how hard a struggle this has been was underlined in a Sports Illustrated interview this month with Carl Lewis, a nine-times Olympic gold medalist who won one of his titles after Johnson was disqualified.
Asked to comment on Bolt's astonishing run, Lewis replied:
"I'm still working with the fact that he dropped from 10-flat to 9.6 in one year. I think there are some issues...Countries like Jamaica do not have a random (dope control) programme, so they can go months without being tested.
"I'm not saying anyone is on anything but everyone needs to be on a level playing field."
As Lewis then pointed out, six men have broken 9.80 seconds.
Three (Johnson and Americans Tim Montgomery and Justin Gatlin) subsequently served drugs bans.
|Carl Lewis, Ben Johnson and Linford Christie in 1988 [GALLO/GETTY]
In 1987 Lewis lost to Johnson at the Rome world championships, a result which would have seemed inconceivable three years earlier when the American ruled supreme at the Los Angeles Olympics.
Lewis was not happy, muttering that there was something strange in the air.
"People forget that I was the first one to speak out about Ben and I got crucified.
"A year later, I was a prophet," he said.
In the northern hemisphere summer of 1988, athletics was still a major sport and a race between Lewis and Johnson in Zurich, won convincingly by the former, became front-page news.
While the world anticipated their meeting in Seoul, Florence Griffith Joyner clocked 10.49 seconds in the women's 100 metres at the US Olympic trials, a mark which has not been approached since and which at the time would have been a national men's record in several countries.
Johnson's expulsion from the Olympic village in Seoul changed dramatically the mood among the media corps who, on the whole, had suppressed any uneasiness about possible widespread doping on the grounds that no big-name athlete had ever been caught.
|Flo-jo retired when random dope testing was introduced [GALLO/GETTY]
Griffith Joyner breezed to victory in the 100 before setting a world record of 21.34 seconds in the 200.
This time nobody in the press box got to their feet and her news conference
afterwards was tense as reporters drew attention to a physique which had altered significantly since the Los Angeles Games.
In the following year, when random dope testing was introduced, Griffith Joyner retired.
Ten years later the American, who never failed a dope test, died in her sleep at the age of 38.
A Canadian government inquiry in 1989 revealed the extent of doping in track and field while Johnson's coach Charlie Francis testified that the athlete had been on drugs since 1981.
Over the next decade, the authorities tightened their controls and a series of scandals shook the sport.
Germany's 1991 double world sprint champion Katrin Krabbe fell foul of the testers and Britain's 1992 Olympic 100 metres gold medalist Linford Christie was later to test positive for nandrolone when in semi-retirement.
In 1997 a talented and articulate American sprinter, who like Lewis was also a champion long jumper, announced her presence on the world stage at the Athens world championships.
At the turn of the century Marion Jones was the face of the Sydney Olympics after announcing she intended to go one better than Lewis and Jesse Owens and win five gold medals at a single Games.
In the end Jones won five medals, three of them gold.
|Disgraced sprinter Marion Jones [GALLO/GETTY]
Of more enduring significance was the announcement during the Games that her shot putter husband C.J. Hunter had tested positive four times for huge amounts of nandrolone during the previous year.
Jones steadfastly denied any involvement in doping, separated from Hunter and had a child by sprinter Montgomery, who in 2002 became the first man to run faster than Johnson.
The chance discovery that the BALCO laboratory in California was supplying drugs to a range of clients, including Jones and Montgomery, led eventually to their downfall.
Jones confessed to being on a drugs regime in Sydney and was stripped of all her subsequent marks and times.
Even Lewis has not escaped suspicion.
In 2003 it was revealed that he had tested positive for three banned stimulants
at the 1988 Olympic trials but was not sanctioned when the US Olympic Committee accepted he had taken the drugs inadvertently in a cold medication.
Bolt and Asafa Powell, the former world 100 record holder, were tested repeatedly in Beijing and their physiques differ markedly from Johnson, who had the torso of a weightlifter.
Both Jamaicans have become understandably exasperated at the suspicions that attends any world record these days.
As Lewis pointed out, this is the reality of modern-day track and field.
"If the sport doesn't have credibility, you're not going to get the sponsors.
"It has to come from the inside out and America has to lead the way.
"We're cleaning things up. But they have to go further.
"Other people have to speak out," he said.