A fun one I had not seen before...

[MNBlue]

Originally Posted by SC Ump

...BR has to run around F2...

This statement in the OP tells me the basepath of the BR was impeded by F2. Since F2 didn't field the ball, F2 does not receive the protection that a fielder in the act of fielding receives, so F2 is guilty of obstruction. Since I don't know of any rule that allows me to bring the BR back to bat after being obstructed, I am going to award the BR first base.

Let's change the OP just a little. Bunted ball up the first base line, F1 comes over to attempt to field the ball, but is late and the ball rolls to F3 who is standing closer to the base than the BR who had to run around F1 after F1 didn't field the ball because F1 was standing in the basepath of the BR. I still have obstruction and award the BR first base and bump all forced runners.

I agree with Mike Crowder. Text book obstruction.