Hitting a baseball or golf ball (in a straight line) are often cited as the most difficult things to do in sports, but it seemed to us that plenty of people on the planet can do them -- even well enough to be successful in the major leagues or as professional golfers. Likewise for returning a tennis serve, finishing a triathlon, competing in a downhill ski event or myriad other activities..
So when it came time to ponder ultimate difficulty, we tried to pick things that even elite athletes in a variety of sports find almost impossible to achieve. Ranking these 10 feats by degree of difficulty ultimately proved impossible, for obvious reasons.
"Every sport has its own particular skill set that is required at a high level," says hockey legend
So here are our 10, in no particular order, accompanied by the thoughts of a notable expert on each sport. Agree? Disagree? Have something you think belongs?