The responses are hysterical. You guys have all picked individuals who can't even stand on their hands, not only are these not the greatest athletes of all time, they lack even basic physical mastery.
This guy is the 2008 olympic all around gold medalist:
Yang Wei, if he isn't the greatest athlete of all time it is probably Kohei Uchimura who won the silver in 2008 and was this year's world champ:
he didnt ask for "all 'round"- as in ability to use all physical facets- although jordan would go close.
the gymnasts you show cannot kick a ball, or have not displayed any skills in terms of hand /eye coordination, plus the competition pool for them is far smaller than that of basketball for instance.
all you could really do is list the best in each sport, then argue what each sport represents.
BB doesnt use kicking for instance
NFL doesnt allow players to perform a whole bunch of skills- so its no good including that sport.
same for baseball...it excludes itself.
T&F could really only include the decathlon.
Soccer excludes itself for many reasons
gymnastics would be in, basketball would also, AFL and Gaelic football would be in, ice hockey also in, MMA arguably in also, pentathlon in also, water polo in, ..you get the idea..