In baseball, interference is an infraction where a person illegally changes the course of play from what is expected. Interference might be committed by players on the offense, players not currently in the game, catchers, umpires, or spectators; each type of interference is covered differently by the rules.

Contents

• 1 Offensive interference
  • 1.1 Verbal interference
  • 1.2 Cases of offensive interference
• 2 Umpire's interference
• 3 Catcher's interference
• 4 Spectator interference
  • 4.1 Cases of possible spectator interference
• 5 Weak interference
  • 5.1 Cases of weak interference
• 6 Common misconceptions
• 7 References

Verb

to interfere (third-person singular simple present interferes, present participle interfering, simple past and past participle interfered)

1. (intransitive) To get involved or involve oneself, causing disturbance.

   I always try not to interfere with other people’s personal affairs.

2. (intransitive) (physics) (of waves) To be correlated with each other when overlapped or superposed.

   Correlated waves interfere to produce interesting patterns, while uncorrelated waves overlap without interfering.

   Where the radio-wave signals of the two radio stations interfere the listener hears nothing but noise.

• interference