Under the measures first proposed in December by MLB's playing rules committee, a runner attempting to score won't be allowed to leave the direct path to home plate to initiate contact with the catcher, or any other player covering the plate.
If judged to be the case by the umpire, the runner will be declared out, even if the player covering home plate loses possession of the ball as a result of the collision.
The guidelines require umpires to consider whether the runner tried to touch the plate and if he lowered his shoulders with the intent of jarring the ball loose via a collision.
A runner will never be called because of the new rule if he slides.
Another new rule prohibits the catcher from blocking the plate unless he has possession of the ball. If the catcher blocks the pathway of the runner while without the ball, the umpire must signal the runner safe.
MLB said the rules will be tried out on an experimental basis for the upcoming season.