But the 6'4" swimmer's superb performances in the final Games of his career have left people not asking if he is the greatest swimmer of all time, but whether he is the greatest Olympian.
If you're looking purely at his medal statistics, there's no argument: with 22 medals, Phelps has four more than the next-best athlete, Soviet gymnast Larisa Latynina.
And judged purely on gold medals, nobody else even comes close: Phelps has been crowned an Olympic champion twice as often as the next nearest athletes. His 18 golds is exactly double that of Latynina, Finnish Athlete Paavo Nurmi, US athlete Carl Lewis and Phelps's fellow American swimming legend Mark Spitz.
So that incredible statistics got us thinking: if there are no other athletes to compare, how about countries? Where would Phelps rank on the all-time medal table if he were an independent sovereign nation with IOC membership?
The almost terrifying answer is that, based on gold medals, he'd be joint 36th, alongside Ethiopia and Austria, one ahead of Argentina, and with nations including Jamaica (13 golds), Mexico (12), India (nine), Ireland (eight), Egypt (seven), Portugal (four).
If you look at medals of all colours, he's a little lower down since he has just two silver and two bronze among his 22 gongs - but his spot in 51st place puts him dead level with India and Portugal, and ahead of nations including Thailand (21), Morocco (21), Venezuela (12) and Pakistan (10).
His records will stop here as has now hung up his goggles at the ripe old age of 27. But the question remains: is he the greatest Olympian ever? Maybe, maybe not. Some say these stats don't lie, others will complain that the nature of swimming allows top competitors more scope to collect multiple medals.
We're just going to say this: Phelps alone, in three Olympics, has won the same number of medals as the billion-strong nation of India has managed in the last 116 years. And that really isn't bad going.
- Sports & Recreation
- Michael Phelps
- Larisa Latynina