[CecilOne]

First, I'm starting this to discuss the result of OBS and not what OBS is or when it occurs, so please stay within that frame.

Second, I'm starting this because I disagree with "determine at the moment that you call (and signal) obstruction what base that runner, in your mind, would have achieved without the OBS - THIS is the base she is protected to (don't wait until later to make this determination!)."

Let's take a simple case. BR-now-R1 is obstructed between 1st and 2nd on a base hit deep to the outfield, but in front of the fielder. OK, an apparent double by the immediate reaction theory. But, ball gets past the fielder, R1 continues to 3rd but is barely beaten by the throw and tagged before touching 3rd.

R1 should be awarded 3rd on the OBS because if there was no OBS, the outfielder would still have missed the ball, R1 would stiil have gone to 3rd and w/o the OBS would have made it.

For that matter, if the throw is missed by F5 and the same thing happens at HP (R1 continues to HP but is barely beaten by the throw and tagged before touching), R1 should still be safe on the OBS award.