What happens if R2 leaves second base before the ball is caught by F9?

When R2 leaves second base before the ball is caught by F9, the proper ruling in accordance with baseball rules is that R2 can be called out on appeal. In this scenario, the critical factor is that a base runner must remain on their base until the ball is caught, as leaving too early can be considered an infraction.

Once F9 catches the ball, the defensive team has the opportunity to appeal the violation. If they successfully appeal that R2 left the base before the catch, then R2 is ruled out. This aspect of the game emphasizes the importance of base running etiquette and the need for runners to wait for the appropriate time to advance, as failing to do so has direct consequences for the runner's status on the bases.

The other choices do not align with the rules governing base running violations, as R2 cannot be considered safe if they commit this infraction, cannot return to second base after an appeal is made (because they are already out), and scoring before the appeal does not negate the rule violation of leaving the base early.