|The Batter becomes a Batter-Runner when the catcher fails to catch the third strike before the ball touches the ground and there are:|
1. Fewer than two outs and first base is not occupied at the time of the pitch, or
2. Any time there are two outs.
It is pretty straightforward. If there is nobody on first and two strikes on the batter, or if there are two outs and two strikes on the batter, then the D3S is in play. “Fails to catch the third strike before the ball touches the ground” means the ball can bounce in front of the plate or right in front of the catcher, as well as any passed balls or wild pitches.
If the game has only one umpire, then the umpire will only signal with his hand that strike three is called, which may look like an “out” signal depending on the umpire. The catcher, who cannot see the signal unless she turns around to look at it, should just know when D3S is applicable and act accordingly. Ditto for the coach – do not get confused because the umpire seems to be calling the batter out, because he is not. With two or more umpires, the base umpire will make a fist by his belt to indicate that the third strike was caught before it touched the ground as an aid for the plate umpire to help with the call. Otherwise, he will point to the ground indicating that the third strike was dropped.
To defend this play, the both the catcher and the first baseman’s reactions are key. The catcher must know when the D3S could be in play, and respond immediately if it occurs. If there is any doubt whether she caught the ball before it hit the ground or not, she should immediately tag the batter just to be sure. This is a crucial habit for a catcher to develop, as it can head off needing to throw to first base, which is obviously a more difficult play to make than just tagging the batter as she starts to run. If there are two outs, the catcher should know to throw down to first (if she cannot apply the tag herself) unless bases are loaded, when she just has to touch home plate when she has the ball.
The first baseman should read where the ball goes if it kicks away from the catcher, and set up on first base (or the orange safety base) as appropriate. If the catcher collects the ball to the left of the first base line (when looking from first base to home), the first baseman should set up to receive the throw in foul territory and yell “Inside! Inside!” to tell the catcher where to throw the ball. If the orange safety base is used, she is allowed to set up on the orange safety base in this case. If the catcher gets the ball on the line or to the right of the first base line, she should yell “Outside! Outside!” and set up on first base as she would for a throw from one of the infielders.
Errors are part of the game, but a misplayed D3S can be particularly painful to watch. Make sure players, particularly the catcher and first baseman, understand the rule and what to do if it occurs during the game.