[greymule]

I like the thought process of a runner not obstructed, getting thrown out because of the actions an obstructed runner had to take.

Yes, that's what I've been tossing around in my head. This is especially problematic to me because OBS is a delayed dead ball, and more often than not, even when we call and signal OBS, the players (especially in SP) continue on, usually with the obstructed runner complaining to us. (On the other extreme, in rec girls' FP, a shout of "obstruction" often brings things to a screeching halt, and runners and fielders all freeze and look at the umpire for direction.)

On the one hand (as rwest has just posted), we are supposed to award the bases that would have been reached had there been no OBS. And this can involve advancing other runners, either as in my play #1 or in cases where preceding runners are pushed ahead. Placing "all affected runners" properly is fine, but what if they react to the OBS and retreat or do something else that puts them in jeopardy?

On the other hand, only the obstructed runner is protected.

In all three plays I posted, awarding 2B and 3B seems like the fair thing to do, but as we all know, the rules don't always produce a fair result.

My original question sprang from a play somebody here at work described to me, wanting to know if the ump in his SP game made the right decision. I assumed I could answer anything he posed, but I had to admit I wasn't sure. So I'm trying to nail down the operative principle.