Major League Baseball has sent a memo to teams clarifying this year's experimental rule intended to limit collisions at home plate, saying runners should not be called safe if the ball clearly beats them.

The rule, announced in February, says a catcher can't block the plate if he doesn't have the ball. There have been several disputed calls, including a pair of decisions in the last five weeks that led to runners being called safe after video review.

The guidelines sent to teams Tuesday say the catcher's positioning shouldn't change the call when the throw clearly is ahead of the runner. They also say if the catcher is entirely in fair territory, he should not be considered to have blocked the plate. Photo examples were included.