If R1 is on first base and attempts to steal second but the catcher’s throw hits the umpire and prevents the out, what is the ruling?

When the catcher throws the ball to attempt a play at second base, and the throw hits the umpire, the ball is deemed dead. According to official baseball rules, specifically regarding interference, if a thrown ball strikes an umpire and that action prevents a potential out, the play is considered dead at that point. Therefore, R1 must return to first base, as the conditions that allow advancement have been negated by the dead ball situation.

The ruling recognizes the umpire's position on the field and how it may inadvertently intervene in the game, making the situation distinct from normal play where the ball might still be in play. This maintains the integrity of the game and ensures fairness in such unexpected circumstances. In this particular scenario, because the advancement is interrupted by the dead ball, R1 does not get to advance and must stay at first base as per the rules.