A defensive technique used by a catcher who is fielding a throw to prevent a baserunner from scoring by blocking home plate with his body while tagging him out.
When blocking the plate, a catcher gets into position just in front and to the left of the plate, crossing the base path from third base to home. The catcher covers the plate in a crouch and prepares to receive the catch as the runner barrels towards the plate. If all goes well, the runner is prevented from reaching the base and the catcher is able to tag the runner out in the process. Because the body of the catcher is between the runner and home plate, the runner is unable to slide and forced to go through or around the catcher. This technique gives the catcher the best chance of putting out the runner.
Because of this advantage, the runner sometimes compensates by attempting to dislodge the ball from the catcher’s glove or hand by colliding with the catcher. Blocking the plate is a dangerous play that has often resulted in injury to the catcher, baserunner, or both, but is a legal technique in major league baseball.