gosh- don't know exactly. if i remember correctly, depending on the sport things were created to not only pass the time away but some created as a form of competition into adult hood, some as a test to win over a woman, other rituals and more. Not sure if there's 1-main source or reason in how but there were many reasons in why or how they got started.
:) did my best and tried on this one Eli, haven't googled it but if you find anything let me know, thanks
Sports were invented in my mother land, "Rome, Italy" in order to find-out who the superior athletes were from different cultures. The educated nobles would tend to mimic the diet, eating patterns and life style of the champions. Doctors performed blood transfusions and a lot of the baseball player's drank sprinkler water to rid of errors and demons.