This was a common rule in a lot of baseball and baseball-ish games I played as a kid. Like ghost runners, a dedicated neutral pitcher, and whether or not you could steal it was something everyone had to decide on when you started playing a game. When you were running between bases someone could peg you rather than having to tag you out. We called it "indian rubber," and I thought it was a universal thing until recently. Apparently it may be a regionalism, and I'd love to know if people outside of Central Massachusetts used this rule and the name.

So, did you have "indian rubber," did you call it by that name, and where did you grow up?