However, not all sports have "points" that scale the same way, so the 10x number is not as easy to apply. For example, Usain Bolt is not literally 10 times faster than the average professional sprinter; his best 100m is 9.58 [4], where as any moderately fit male can easily hit sub 20 seconds, and I believe any professional sprinter will go under 11 seconds. Nevertheless, I'd guess that in the 100m sprint, a difference of 1 or 2 seconds represents an order of magnitude (or two) difference in ability, even if it's only 10-20% of the time. What kind of odds would you give him in a race against an "average professional"? 10:1? 100:1? 1000:1? Usain is roughly as far above other pro sprinters as Gretzky and Lemieux were against other pro hockey players.
I'd also mention that "fame" is a bit of an x-factor. The world is not a perfect meritocracy and there is so much luck and so many external factors that go into being famous that it's not necessarily true that only famous scientists/musicians/writers are the only ones who are 10x. Of course, the famous folks are the only ones I can reasonably use as examples, and fame likely correlates with talent, though that talent may just be at being famous :)
[1] http://www.quanthockey.com/Distributions/CareerGoals.php [2] http://www.nhl.com/ice/player.htm?id=8447400 [3] http://www.nhl.com/ice/player.htm?id=8448782 [4] http://en.wikipedia.org/wiki/Men's_100_metres_world_record_p...