LONDON With one final splash, the greatest Olympian in history finished his career Saturday night.

Michael Phelps extended his Olympic record by winning his 22nd medal in the 4x100 medley relay as the Americans capped a superb swim meet with one last gold medal. Phelps’ 18th overall gold medal – also a record – was placed around his neck at 9:05 p.m. London time.

“I’ve been able to do everything I wanted,” Phelps said later, explaining why he was retiring while still on top. “And I think if you can say that about your career, there’s no need to move forward. Time for other things.”

To me, there is no real debate. The numbers say it, and with my own eyes I’ve seen it. Phelps is the best Olympic athlete ever. He has dominated his sport for three successive Olympics, ruling it for close to a decade with a big grin and fantastic closing speed.

And yet there is a debate. Sebastian Coe, who is the head of these London Olympics, was a two-time gold medalist himself as a middle-distance runner for England. He told a group of reporters at a recent press briefing in London that while Phelps was “the most successful (Olympian), my personal view is that he is not the greatest.” He also called Phelps’ number of medals “a pretty good haul.”

So who did Coe think was the greatest? He didn’t pick a single name, but said the issue could become a “great global pub game.” Coe listed five-time gold medalist British rower Steve Redgrave, two-time British Olympic decathlon winner Daley Thompson, U.S. runner Jesse Owens and Romanian gymnast Nadia Comaneci as possible contenders.

All right, before we start into that… “a pretty good haul”?

Seriously? Calling 22 medals a pretty good haul is like calling Big Ben a pretty big clock.

There are many Olympic athletes who gladly surrender years of their life to win a single medal. Phelps has pushed the medal record so high that even though he claims it isn’t untouchable, in my view we won’t ever see anyone ever break the mark.

And it could have been more than 22. David Marsh is the coach of Charlotte’s SwimMAC Elite and a U.S. Olympic assistant coach. Marsh said that if swimming was spread over two weeks at the Olympics instead of shoehorned into eight days that Phelps would have far more medals because he wouldn’t have to pick and choose among events.

“I get the romantic appeal of the Olympic decathlon,” Marsh said. “But Michael is the decathlete of swimming. He swims all four strokes. If the program was a two-week program, he’d have 35 medals. I’m serious.”

And while 35 might be an exaggeration, nothing has seemed impossible with Phelps the past eight years. He won six gold medals in Athens in 2004, went an astounding eight-for-eight on gold in Beijing in 2008 and then won four more (in seven tries) in London. FINA, the international swim body, presented Phelps with a surprise trophy Saturday night that labeled him “the greatest Olympic athlete of all time.”

“I’ve looked up to Michael Jordan my whole life because he’s done something nobody else has ever done,” Phelps said later. “And he is the greatest basketball player to ever play the game. And you know what? I’ve been able to become the best swimmer of all time.”

At 27, Phelps has finally seemed vulnerable in these Olympics, finishing in fourth place in one race and winning silver in two others.

“He’s been a real leader this time,” said Dana Vollmer, another U.S. swimmer. “He’s shown you can have great performances, but that you can also be extremely classy getting second.”

But still, Phelps has been ridiculously good again in his final Olympics. Most athletes would kill for a four-gold, two-silver career. This was only Phelps’ third-best Olympics.

There have been many wonderful Olympians. Owens won four gold medals in 1936 in Berlin at an Olympics that Nazi organizers were hoping to use as propaganda to prove Adolf Hitler’s theories of Aryan racial superiority.

Comaneci was a stunning gymnast who scored the first perfect “10” ever awarded in 1976. Decathletes like Thompson, who compete in 10 diverse track and field events, are undoubtedly the most versatile athletes in the Olympics.

There are athletes who have qualified for more Olympics than Phelps and won their golds over a longer span of time. And to be sure he does have the inherent advantage of competing in a sport in which many medals are awarded in many different events.

But gymnastics has multiple medal opportunities, too. So does track and field. And Phelps has surpassed everyone. He has the perfect body for swimming – a 6-foot-4 frame, a very long torso, size-14 feet – but he also didn’t take a day off for six years at one point.

Ryan Lochte, Phelps’ friend and rival, proclaimed before these Games: “This is my time.”

Well, no, it wasn’t. Lochte and Phelps split their two match races in the Olympics, but Phelps ended up winning more medals than Lochte (or anyone else) and performing better overall.

The final individual Olympic race of Phelps’ career on Friday night was instructive. Phelps was seventh at the halfway point of the 100 butterfly and then came back to pass everyone in the last 50 meters. That he could still summon the strength to do that speaks volumes about his pain threshold and his talent.

Phelps has been more nostalgic in these Olympics and more self-aware. He’s been keeping a journal. He said if he were to write something about Saturday night, it would be only three words: “I did it.”

Phelps said he cried with his longtime coach Bob Bowman Saturday night in the warm-down pool after his final event, his tears hidden behind his goggles.

In his mind, Phelps has been checking off the “lasts” all week. Last team meeting. Last practice. Last race.

Now it is time for firsts. Phelps will travel and make some appearances. He’s not really sure what’s next, but he swears he’s not going to make a comeback.

As he left a news conference Saturday night, a questioner asked the other swimmers on the relay if they really thought Phelps was finished for good.

“Yes,” Phelps interrupted, walking out of the room. “Yes.”