Lance Armstrong's chances of winning a record sixth Tour de France are no more than 50-50, according to fellow five-time winner Bernard Hinault.
Armstrong moved into the yellow jersey on Wednesday after a blistering US Postal team time trial.
But Hinault, who dominated cycling for much of the eighties and is now one of the Tour organisers, is not convinced.
"He's not looked that good this year and everyone saw how he struggled in the mountains last year," said Hinault.
"So I'd say his chances of winning are only 50-50 at best."
Armstrong and Hinault are part of a select quintet to have won global cycling's biggest annual event five times. The others are Eddy Merckx, Jacques Anquetil and Miguel Indurain.
But even if Armstrong wins a sixth, Hinault says he has no right to call himself the best ever.
The Frenchman said: "It's wrong to compare eras. He is at the top of his and I was at the top of mine, as were all the other five-time Tour winners.
"Should Armstrong win six, he will be great. But greater than Merckx, Anquetil or Indurain - I'm not so sure."
Hinault believes the stage is set for a new face to wear the winner's yellow jersey in Paris at the end of July.
He said: "For me, the three key men are Jan Ullrich, Tyler Hamilton and Roberto Heras. And this year's course means they all have a strong chance."