Not for Sebastian Coe.
Coe, the two-time gold medallist in the 1,500 metres and head of the London Games, is not ready to anoint Phelps as the supreme Olympian.
"You can probably say that clearly, self evidently, in medal tally he's the most successful," Coe said Wednesday. "My personal view is I am not sure he is the greatest, but he is certainly the most successful. That goes without saying."
The American swam the anchor leg of the winning U.S. 4x200-metre freestyle relay Tuesday night to surpass Soviet gymnast Larisa Latynina for most career Olympic medals. Latynina won 18 medals at the 1956, 1960 and 1964 Olympics.
Phelps, who won a record eight gold medals at the 2008 Beijing Games, has a total of 15 gold, two silver and two bronze. He is competing in three other events in London and can take the record even further.
So who, Coe was asked, would he pick over Phelps?
He started with a crack: 'Well, modesty prevents me from....No. That's a joke."
"This is the global pub game," said Coe, who won his gold medals at the 1980 and 1984 Games. "Who is the greatest Olympian of all time? I could go around this whole room, we'd all come up with different interpretations on that. But you have to say he's up there. But whether he is the greatest, in my opinion, probably not."
Again, Coe was pressed to name his choice as the greatest Olympian.
"I could throw out a a whole series of names," he said.
Coe offered up two British athletes — five-time gold medallist rower Steve Redgrave and two-time decathlon champion Daley Thompson. He also mentioned Jesse Owens, who won four gold medals at the 1936 Berlin Olympics, and Romanian Nadia Comaneci, who became the first gymnast to score a perfect 10 at the 1976 Montreal Games and won a total of five Olympic golds.
Notably missing from Coe's list: Carl Lewis, who won four consecutive gold medals in the long jump and a total of nine gold.
Coe, meanwhile, said he had attended 16 sports during the first five days of the games. Despite problems with empty seats at some of the venues, he said the atmosphere has been electric.
"I have been absolutely blown away by the noise, the vibrancy, just the humour and excitement," he said. "Clearly the public has come out in force to support these games. They have embraced these games. Our venues have been rocking."
Coe singled out the buzz at weightlifting.
"You suddenly felt that you were in an arena filled with people from Kazakhstan," he said. "It was extraordinary"
Coe said there had been seven world records and 30 Olympic records in the opening five days. While China and the United States are battling again for medal supremacy, France, South Korea and Germany are among other nations doing well in the standings.
"The big teams are up there, but they are also being pushed really hard by other teams that we might not have seen so obviously on the radar screen," Coe said.