Obstruction vs Interference

[rwest]

Some questions regarding obstruction vs interference.

1. How close to the ball does the defensive player have to be in order to be "in the act of fielding the ball"?

2. Are there some circumstances where the defense can position themselves in the base line at the start of the pitch and NOT be called for obstruction?

Case in point: R1 on 1B. F3 in the base line a couple of feet from the bag at the start of the pitch. Slow roller down first base line. F3 never moves but is waiting on the ball. The ball is rolling toward F3. Is F3 in the act of fielding the ball? R1 runs into F3 while the ball is probably 10 - 15 feet away. Is this obstruction or interference? F3 realized the ball wasn't going to get to her so after she became untangled with R1 she moved up to get the ball. She then stepped on first for the out. There was never a play on R1 so there was no obstruction call. Would it matter if the ball was hit sharply to F3 so that she did not have to move up to get the ball? Does R1 have to avoid F3 in this situation? Does F3 have to get out of the way if she has time to get to the ball and still make a play or can she stand in the base line on a slow roller like I've described? Obviously, if the ball had been hit down third base line, this would have been obstruction.

3. If the defense and offense arrive at the same point in the base line/base path at the same time, do we have obstruction, interference or a live ball train wreck? For example, assuming the same play as above except that F3 is playing back and farther in toward second. A ball hit between 1st and 2nd. F3 is moving up to field the ball and R1 is advancing toward 2nd. They both arrive at the same spot at the same time causing a collision? What's the call? If R1 had arrived first and F3 had accidently tripped her, even though F3 was in the act of fielding, would we have Obstruction? If F3 arrived first and R1 ran into her, that's an obvious interference call.

Thanks!
Randall