Obstruction or not?

[IRISHMAFIA]

Originally Posted by IamMatt

14U batter hits grounder to F5. Right-handed F3 has her foot planted on the white portion of 1B and her glove out waiting for the throw.

Dumb fielder needs to learn how to play her position

F5's throw is off a few degrees to her right (or clockwise) so that rather than going straight to F3's glove, the ball will intersect the baseline a foot or two towards home plate.

This causes F3 to turn or pivot and reach across the lane in front of the orange portion of 1B to make the catch just as BR is arriving at the base, so that F3 is blocking both sides of the base before receiving the ball and her momentum is also causing her to step with her not-planted foot across the baseline, leaving a footprint about a half-foot into foul territory and about a foot in front of 1B.

To this point, it is nothing.

In order to avoid a collision, BR puts the brakes on, which slows her enough so that the ball gets to F3 before BR hits 1B.

Sounds like OBS.

What it BR had not slowed down and had collided with F3 just before the catch?

OBS assuming BR did not reach 1B at approximately the same time. BEFORE everyone goes off, I would not signal OBS at this point because it may be an indication to the coach the now-runner is protected to 2B. Yes, I know that isn't the umpire's problem, but it's a small measure of preventive umpiring that will save me a headache while not causing any influence on the game.