A mid-19th c. rival of baseball (then NY style) had a rival - the "Massachusetts Game." The Massachusetts game allowed defensive players to hit the runner for an out. They also allowed overhand pitching and no catching one hoppers for an out, which didn't make it to pro ball until after the first pro league - the NA.
So, what would baseball be like if you always could hit the runner for an out (to this day)? More equipment? Injuries? Change in strategy?
Crazy hypothetical, I know.