Old Rule: In the past, when a game tied in the bottom of the fifth inning or later and was called because of rain, the stats counted, but the entire game was replayed.
New Rule: Now, the game will be suspended and picked up from the point of the suspension the next time that the two teams play in the same ballpark. If there are no remaining games in that park, it will be picked up from the same point in the visiting ballpark the next time the two teams play there. And if it's the last regularly scheduled game between the two teams, it will be canceled. If the game impacts a post-season berth, it will be replayed from the beginning.
Old Rule: There was no time limit for a pitcher to throw a pitch.
New Rule: With no runners on base, the pitcher must throw a pitch within 12 seconds of the time that the pitcher has the ball and the batter is in the batter's box and "alert" to the pitcher.
Old Rule: When pitching out of the stretch position with no runners on base a pitcher had to bring his hands to a complete stop.
New Rule: The pitcher no longer has to bring his hands to a complete stop when pitching out of the stretch position with no runners on base. He must stop his hands if there are any runners on base.
Old Rule: A pitcher could not wear a multi-colored glove.
New Rule: A pitcher can wear a multi-colored glove provided the umpire does not deem it distracting.
Old Rule: Players could run into the dugout to catch a foul ball.
New Rule: Players may not enter the dugout to catch a fly ball. They may reach into the dugout, but must have both feet outside the dugout.
Old Rule: If a position player intentionally scuffed or defaced the ball, a ball was called and the player was warned.
New Rule: If a position player intentionally scuffs or defaces a ball, the player will be ejected and receive an automatic 10 game suspension.
Old Rule: On a dropped third strike call a player could run to first until he reached his dugout or defensive position.
New Rule: A batter will not be allowed to run to first base if he leaves the dirt circle around home plate, unless he does so in an attempt to reach first base. Also, a player may go outside of the three-foot lane in foul territory for "the sole purpose of touching first base."
Old Rule: A player hitting a game-winning home run would not be allowed to score if a runner on base abandoned the base paths thinking the game was over.
New Rule: The player hitting the home run will be allowed to circle the bases and score if a runner on base abandoned the base paths thinking the game was over as long as there were less than two outs when the home run was hit. If there were two outs, the runner will be called out and the inning will end without the hitter being allowed to score.
In addition, the committee adopted changes to official scoring, including a new definition of "ordinary effort" when determining hits and errors. They also added casebook comments to guide official scorers, setup an appeals process to appeal official scorer's decisions and reorganized certain scoring rules. Those changes will not directly impact how the game is played and will only impact official scorer's decisions on plays and help guide them in making decisions.