<P> When a fielder hinders a baserunner, the situation is called obstruction, not interference . Baseball commentators will often mistakenly refer to obstruction as interference . </P> <P> Not all physical contact in baseball is interference . Accidental contact that has little or no effect on play will usually be ignored; physical contact must result in an advantageous situation for the offense to be considered offensive interference . Nor must physical contact occur for interference to be called . A runner may interfere with a fielder simply by hindering the fielder's ability to attempt to make a play on a batted ball . </P> <P> If a base runner is hit by a fair - batted ball while standing on a base, the runner is out, unless the ball has already passed an infielder or the infield fly rule has been declared . The base is not a sanctuary . </P> <P> Being in contact with a base may protect a baserunner from being called out for interference in the case of a fielder attempting to field a batted ball . </P>

What happens if a base runner is hit by a thrown ball