MLB To Test More Rules Changes During 2023 Atlantic League Season

Image credit: Tracy McGrady #1 of the Sugar Land Skeeters warms up in the bullpen before throwing against the Somerset Patriots at Constellation Field on May 10, 2014 in Sugar Land, Texas. (Photo by Bob Levey/Getty Images)

Major League Baseball announced Tuesday it is implementing three experimental rules changes in the partner Atlantic League for the 2023 season.

Beginning April 28, the Atlantic League will allow for a designated pinch-runner and pitchers will be allowed to step off the rubber only once (as opposed to two times in MLB and the minor leagues). In addition to the new rules, the league is continuing the double-hook DH, which ties teams’ having a DH to how long a starting pitcher lasts in a game.

The rules are as follows:

• Designated pinch-runner: Each club will list a player who is not otherwise in the starting lineup as a designated pinch runner. That player may then be substituted at any point into the game as a baserunner. The player who is substituted for, as well as the pinch runner, may then return to the game without penalty. 
• Pitcher disengagement: Pitchers may step off the rubber for a pickoff throw or other disengagement only one time per at-bat. If pitchers attempt a second pickoff or have another disengagement within an at-bat and no out is recorded, a balk will be called.
• Double-hook DH: Teams can use the designated hitter throughout the game provided their starting pitcher completes at least five innings. If the starter fails to make it through the fifth, the club loses the DH for the remainder of the game. A similar rule was first introduced in the league in 2021 and modified in 2022.

MLB first reached agreement with the Atlantic League to use the league as a laboratory for experimental rules changes in 2019, when the league was independent. MLB designated the Atlantic League a “partner league” in 2020.

Some, but not all, of the previous rules changes in the Atlantic League have eventually made their way to MLB. The first batch of experimental rules changes introduced in the Atlantic League in 2019 included a three-batter minimum for pitchers, increasing the size of the bases from 15 to 18 inches square and the requirement that two infielders be on each side of second base when the pitch was released.

MLB adopted the three-batter minimum in 2020 and introduced the larger bases and infielder positioning requirements in 2023.

Other rules introduced in the Atlantic League were not adopted further. These included a ban on all mound visits except in case of injury, batters being allowed to run to first base on wild pitches, passed balls or dropped pitches regardless of count and the mound being pushed back by one foot to 61 feet, 6 inches.