Do you want to be great (or at least attempt to be great)? Then you MUST specialized (except for 0.00000000001% of people). And start in the womb. Tiger Woods, Mia Hamm. . .
Do you simply LOVE being athletic and enjoy sport�but have no urge to be the very best? Then play all the sports you can.
In other words, there is no one answer. If a child is gifted early enough to notice, and some (reasonable) adults can see that talent, I believe in focusing, specializing for the potential of greatest few people reach. But it all depends on what you want to achieve.
I think soccer requires such high skill to excel that it is more likely NOT to have multi-sport athletes.
