File this entry under Pure Speculation. I was reading an article on the history of baseball earlier this year, and learned about the "Massachusetts rules" form of the game that existed in the mid-1800s. It seems that the local brand of the game was superceded by the New York game - drats! - and the Massachusetts game faded from memory even here in its home. One particular rule peaked my interest. From "The Rules of the Massachusetts Game," by the Massachusetts Association of Base Ball Players. May 13, 1858.
"If a player, while running the Bases, be hit with the Ball thrown by one of the opposite side, before he has touched the home bound, while off a Base, he shall be considered out."
Hmmm... that's interesting. We played under that rule at the Agassiz schoolyard in the early-mid 1960s. We frequently played with different types of rubber balls, so there was no harm to throwing a player out by hitting him as he ran. This raises to obvious possibilies. First, maybe the idea of throwing runners out by hitting them is in some way natural, and came about as a logical result of boys making up rules while playing unsupervised games. That would have been my guess until recently.
The other possibility is more interesting. Could this rule, formerly an official part of the Massachusetts game, have been passed down by generation after generation of boys on fields and lots long after the "New York" rules had been adopted in official games? The idea that the boys of Jamaica Plain, playing without supervision, passed on this rule summer by summer, older brother to younger, over one hundred years certainly can't be proven any way I know of, but it certainly intrigues me. I've never seen it suggested in print, so I thought I'd put it out there in the Intergoogle on the chance that someone might have considered the possibilty before now.