A runner is on third base with 1 out. A fly ball is hit to the outfield and caught. The runner tags at 3rd base as if to go home and then decides to go back to 3rd. The caught fly ball is thrown back to 3rd. Is this a tag out or a force out at third?
Since the runner already tagged up at third base, if the third baseman was to retire the runner at third he would have to tag him. Since the runner has already tagged up, he is not forced to return to the base and can advance or return at his own peril, meaning that he would have to be tagged with the ball to be out.