The ESPN site listed above really brings home the point that there are sports that require a higher skill level than others and sports that require a higher endurance level and yet other sports that require a higher strength level. Which is more difficult to acheive? If you take David Beckham (soccer) and put him in a boxing ring - no contest. If you take Michael Jordan (basketball) and put him on the tennis court - no contest.
In general I agree with the ESPN site - except gymnastics should be higher (strength, skill, endurance).

"...And I will strike down upon thee with great vengeance and furious anger those who attempt to poison and destroy my brothers. And you will know my name is the Lord when I lay my vengeance upon thee."
- Jules' version of Ezekiel 25:17