Rather than ban home plate collisions outright, Major League Baseball and its players adopted a rule limiting them this season.
In what both sides said was a one-year experiment, the rule allows collisions if the catcher has the ball and is blocking the runner's direct path to home plate, and if the catcher goes into the basepath to field a throw to the plate.
The new rule, 7.13, states "a runner attempting to score may not deviate from his direct pathway to the plate in order to initiate contact with the catcher (or other player covering home plate)." A runner violating the rule shall be declared out, even if the fielder drops the ball.
Along with the rule, the sides agreed to a pair of comments that umpires use to interpret the rule. The first comment says, "the failure by the runner to make an effort to touch the plate, the runner's lowering of the shoulder, or the runner's pushing through with his hands, elbows or arms, would support a determination that the runner deviated from the pathway in order to initiate contact with the catcher in violation." The comment says players who slide appropriately are not in violation of the rule.
The second comment says that "unless the catcher is in possession of the ball, the catcher cannot block the pathway of the runner as he is attempting to score." The runner shall be declared safe if the catcher violates that provision. In addition, it is not a violation "if the catcher blocks the pathway of the runner in order to field a throw, and the umpire determines that the catcher could not have fielded the ball without blocking the pathway of the runner and that contact with the runner was unavoidable."
The rule serves as a compromise between the league and the player's union.
Sources told ESPN The Magazine's Buster Olney that Major League Baseball's playing rules committee adopted a must-slide/no block rule which would have required the runners to slide and the catchers to give the runners part of the plate.
However, the MLBPA would not approve that rule for 2014 because they felt that there was insufficient time to train catchers and runners to adjust their behavior before the start of the season. The discussion over that particular distinction is why spring training opened without the rule fully defined.
The umpire crew chief can use the new video-review system to determine whether the rule was violated.
Debate over plate collisions has intensified since May 2011, when San Francisco's Buster Posey was injured as the Marlins' Scott Cousins crashed into him at the plate. Posey, an All-Star catcher, sustained a broken bone in his lower left leg and three torn ligaments in his ankle, injuries that ended his season.
"Just reading through it, the main thing it does is eliminate the malicious collision," Posey told ESPN's "Baseball Tonight" on Tuesday morning. "If the catcher is not set up right on top of the plate, it doesn't allow the runner to run through him."
Posey said the tweak to the rule would not alter the way he prepares for the season as a catcher or as a baserunner.
"For the most part, I think it'll stay pretty much the same," Posey said. "We've never been taught to set up right on top of the plate; we've always been taught to give the runner a little bit of the plate.