yet another baseball rules question

True. But if the firstbaseman is right at the bag when fielding the ball, he will often tag the bag and throw to second while yelling “TAG!” to alert the shortstop that he must tag the runner coming in.

To get back to the OP: the runner on 1B (R1, to use the common short hand on umpire discussion boards) cannot be forced out because the force was removed when the batter-runner (BR) was retired when 1B was tagged (7.08e). R1, once on 2B, cannot return to 1B once the pitcher is on the mound (7.01). If legally going backwards, the runner has to touch the bases in reverse order (7.02). But under no circumstances can the runner run the bases backwards in order to “make a travesty of the game.” (7.08i).

It’s nice having a rulebook in my desk at work. :slight_smile: