• A runner sliding into second has to make "a bona fide attempt" not just to slide into the base, but also to "remain on the base."
• Runners will not be allowed to change their "pathway to the base" in the middle of a slide to break up a double play.
• Baserunners can no longer use a "roll block" on an infielder to break up a double play. Essentially, that means they can't start their slide in midair and make contact with the infielder at or near the knee, with either a leg, arm or the body, before they've made contact with the ground.
• If a runner makes contact with the infielder illegally, both he and the batter would be called out.
• But if the runner makes contact with the infielder while attempting a "bona fide" slide, he would not be called for interference.
• Finally, because of these new safety measures, MLB and the union have agreed to allow umpires to more strictly enforce the "neighborhood play" and use replay to review that play for the first time.