We've been taught that interference is an infraction which the team on offense commits. However, there is one case where the defense can commit interference – defensive interference, commonly known as "catcher's interference." All other infractions by the defense that impede offensive players (base runners) are obstruction.
We're going to look closely at two related forms of defensive interference and call them by their familiar names:
The definition of defensive interference is very simple – just 18 words: "Defensive interference is an act by a fielder which hinders or prevents a batter from hitting a pitch."
The rule specifies "fielder" but in reality the catcher is the culprit in 99.9% of cases which is why it's commonly known as catcher's interference. That said, there is one edge case in which another fielder could possibly "hinder or prevent" a batter from hitting a pitch – that is with an infielder charging on a bunt attempt, but charging so aggressively that he somehow contacts the bat during the attempt, or conceivably the pitched ball before it arrives at the bat. But it's hard to picture this.
By far the most common scenario in which you have catcher's interference is the catcher placing his mitt such that it touches the bat during a batter's offer at a pitch. Sometimes the bat only glances the mitt and the batter puts the ball in play. Sometimes the bat hits the mitt solidly (sometimes injuring the catcher).
But wait. There's one more consideration. If the ball is put in play when the interference happened you have a delayed dead ball. Let the play continue, then call time when the play is complete. We explain in the next section how to handle this.
If, on the other hand, the ball is not put in play (either swing and miss, or foul ball), just call time and enforce the penalty. Let's look at both of these scenarios:
Ball put in play: delayed dead ball
If there is catcher's interference and yet the ball is put in play, don't kill the ball. Allow action to continue. Once all action on the play has concluded, call time. At this point the team manager has the option of accepting the result of the play, OR, accepting the penalty. If the batter was put out on the play, he's probably going to accept the penalty. But not necessarily.
Take this scenario, for example. Say there are no outs and a non-forced runner on third (R3) scores on the play. The manager might want to overlook the interference and accept the out at first in order to get the run. Otherwise, if the manager decides to accept the penalty instead of the play, then R3 would have to return to third base and the run would come off the board.
Ball not in play: dead ball (slightly delayed)
If the ball was not put in play, there are no options. Just kill the ball, vocalize the infraction, and send the batter to first base. Other runners advance if forced. However, there's one big exception, so pause for a moment before you kill the ball to ensure you're not stepping on the exception.
To wit: If a runner successfully steals third base on the play (or home, for that matter), and if the catcher's interference occurred on a swing-and-miss (not a foul ball), then the manager might want to accept the result of the play (ball or strike) and keep the stolen base rather than send the batter to first and send the other runner back. The point, then, is to not rush calling time. First ensure there is no action on the bases.
The catcher's balk
I'm adding this information about the catcher's balk because it seems logical to group all of these infractions by a catcher together. There are two ways that a catcher's actions can cause you to call a balk (or illegal pitch with no runners on base).
Rule 6.01(g). If, with a runner on third base and trying to score by means of a squeeze play or steal, the catcher or any other fielder steps in front of home base without possession of the ball, or touches the batter or the bat, the pitcher shall be charged with a balk ("catcher's balk"). The batter is awarded first base on the interference ("catcher's interference") and the ball is dead.
The upshot here is that if the catcher commits defensive interference when a runner from third is stealing home, you don't have any manager options. Instead, you have this:
- Call time, killing the ball;
- Award the batter first base on the catcher's interference;
- Award the runner from third home on the balk (nullify the out if he's out at home and score the run); and
- Award other runners (if any) one base on the balk.
And finally, Rule 5.02(a). If a catcher leaves the catcher's box before the pitcher delivers the pitch (as when giving an intentional walk), the pitcher shall be charged with a balk (with runners on base), or with no runners on, an illegal pitch (ball to the batter).
Truth is, I've never seen this enforced. Umpires (even in pro ball) appear to give a lot of leeway. In youth ball you sometimes see a catcher set up way outside the catcher's box for an intentional walk; in that case, I'd just instruct the catcher to get back where he belongs.