BEIJING -- Michael Phelps isn't just the best swimmer in the world, he's the most versatile. He's the world-record holder in the two events that include all four strokes: butterfly, backstroke, breaststroke and freestyle. And he's world class in three of the four strokes individually.
What makes Phelps so good? ESPN.com asked his coach, Bob Bowman, to break him down by each discipline.
Phelps owns the five fastest times in history in the 200 fly and five of the top 10 in the 100. Yet he's done it by breaking one of the long-standing butterfly tenets: He breathes every stroke, barely lifting his chin above surface level. For years, coaches drilled their butterfliers to breathe every two or three strokes.
"I think he just has a better rhythm when he breathes every stroke," Bowman said. "He's getting more air, and that's a good thing. When he picks his head up every stroke he balances better."
Phelps' fulcrum is an abnormally long torso -- it's the reason why he's anatomically perfect for his sport, and especially this stroke. His immense wingspan allows him to cover more area per stroke than his competitors, and his double-jointed ankles serve as virtual flippers to power his dolphin kick.
Phelps in pictures
Get a better look at each of Michael Phelps' strokes in our ZOOM gallery. Launch
Phelps doesn't swim this in individual events, but he's still an excellent backstroker. At last year's national meet, he posted times that were the second-fastest in the world in 2007 for both the 100 and 200 back. Bowman worked hard to refine Phelps' pull and streamline his body position in the water.
"He gets better distance per stroke, holds onto more water per stroke," Bowman said. "He's also a little flatter [in the water] than he used to be. And he's stronger."
This is the closest thing Phelps has to a chink in his individual medley armor. It's the only stroke he's not capable of dominating, but he's hardly bad at it.
"It's so much better in every way," Bowman said. "What we worked on is coordinating his arms and his kick, and activating his core muscles in every way."
The breaststroke is all about timing and rhythm, keeping the pull and kick working in synch. And Phelps' dry-land weight training, which he'd never done prior to last year, has enhanced his core strength.
Watch Phelps swim this stroke and it might evoke some memories of former Russian freestyle great Alexander Popov. His stroke was so powerful and efficient that he never appeared to be working as hard as his competitors -- yet he always beat them. In developing Phelps' stroke, Bowman studied Popov's technique.
"We worked on trying to do some drills like Alex, riding the stroke. He was always a very good kicker. What we've worked on most is distance per stroke, maximum amount of water pulled."
Starts and turns
Phelps has no wasted motion leaving the blocks, throwing his arms straight forward and into a tight streamline position as he enters the water. From there, his incredible dolphin kick rockets him the maximum 15 meters underwater (go any farther and it's an automatic disqualification).
The same dolphin kick and streamline have made Phelps' turns the best in the world. Watch how much he separates himself from competitors underwater. Hard work on technique, coupled with weight training, has turned what once was a liability into a strength.
"I think Michael has this incredible feel for the water that I do not think is taught," said four-time U.S. gold medalist Lenny Krayzelburg. "It's natural. His hands are so synchronized underneath the water, with almost no bubbles. That is so rare. You either have it or you don't. But it cannot be ignored how the guy works his butt off."
Pat Forde is a senior writer for ESPN.com. He can be reached at ESPN4D@aol.com.