KEY POINTS:
For many, the main interest in the Tour de France this year will not reside in the slow emergence, over three weeks and 3500km, of the overall winner.
The burning issue is this: can the Tour de France - and professional road-racing with it - regain the credibility blighted by seemingly endless successions of doping scandals with a fresh start which got under way from Brest last night?
Questioning the sport's long-term capacity to clean itself up has become a depressing norm. But there are some encouraging signs.
All the Tour 2008 teams have been subject to increasingly strict controls from the usual anti-doping authorities over the past six months - in the shape of the biological passport. The passport, which is essentially a record of riders' long-term physiological values, shows up any major, potentially suspect changes in those values.
Any riders showing such changes are stopped from racing. For the first time, the Tour includes testing for human growth hormone and this year has seen the introduction of a "chaperone" system, in which riders due for testing are accompanied from the finish line to the mobile anti-doping lab.
Apart from these measures, three top-tier teams - CSC-Saxobank, Garmin-Chipotle and Columbia - are running sophisticated and far-ranging anti-doping programmes of their own, run by independent authorities.
It is no coincidence that all three of these teams have recently succeeded in bringing in new, badly-needed sponsors to the sport.
A Columbia representative said that one of the reasons the company had decided to back the team was "because of its dedication to fair competition".
"Cycling has developed a much more human face this year," Tour race director Christian Prudhomme said recently. "So far in 2008, the racing has been different."
His implication was that the anti-doping battle, if by no means won, has at least caused some significant changes.
The Tour has drawn its own line in the sand as well. Last year's winner, Alberto Contador, is not taking part because his team, Astana, were entangled in the doping scandals of 2006 and 2007.
Contador was not part of the team when the scandals broke. The Spaniard signed for Astana in January.
But the precautionary measure has sent out the strongest of warnings to the teams involved this year, that not even winning the Tour is enough to guarantee a place in the race.
One hugely important indirect consequence of Contador's absence is to leave the fight for the yellow jersey wide open. The media spotlight has swung on to Cadel Evans, the Australian runner-up in last year's race.
But as Evans' team manager at Silence-Lotto, Marc Sergeant, puts it: "With no Contador, everybody sees this as the chance of a lifetime to win. Not just Cadel."
The Tour has attempted to turn the uncertainty up to a maximum by cutting out the traditional opening prologue and time bonuses for stage wins.
This means that the fight for stage wins and top placings, at least initially, will be much more intense than usual.
As Britain's top sprinter, Mark Cavendish, pointed out: "The Tour is already a different event to all the others. With the overall contenders and guys looking for stage wins all trying to be in the front in the last 50km, it's normally five or six kilometres an hour faster than any other race."
Tuesday's 29km time trial is the first real test of strength and on Thursday, the race's first summit finish, at Super-Besse deep in the Massif Centrale mountains, will be another important challenge.
However, the battle for yellow will really come alight in the Alps in the third week. Tackling the Bonette-Restefond, France's highest mountain pass, which peaks at a lung-bursting 2802m, will be one key moment.
The infamous Alpe D'Huez climb, cycling's most prestigious ascent, will be another.
Predicting a winner, as the race enters uncharted waters in the fight against doping and given that there are so few clear favourites, is a risky business.
But as Prudhomme told the French newspaper L'Equipe: "Whatever happens between now and Paris, we won't come out of this the same."
Prudhomme was not only talking about the results from the racing. In the long-term, the results from the anti-doping labs will be far more important.
- INDEPENDENT