MLB Moving Mound Back, Testing New DH Rule During 2021 Atlantic League Season

Major League Baseball and the Atlantic League of Professional Baseball (ALPB) jointly announced a new set of experimental rules will be tested during the 2021 Atlantic League Championship Season.

Chief among them are the “double-hook” rule, which will be in place for the entire season. Teams will begin each game with a designated hitter but lose the spot in the lineup as soon as the starting pitcher is removed.

The hope is that the change will incentivize teams to leave their starting pitchers in longer. Roughly 90% of starts during the 2020 MLB season lasted less than seven innings.

The double-hook rule also would appear to be a compromise of the traditional style of National League baseball and the American League’s use of the designated hitter.

Los Angeles Dodgers president of baseball Andrew Friedman proposed a similar hybrid rule last year that would see teams begin games with a designated hitter and then relinquish it once the starting pitcher is pulled.

The NL adopted the DH during the abbreviated 2020 season but reverted back to pitchers hitting this year after MLB and the players’ union failed to reach an agreement. However, there’s speculation the DH could permanently return to the NL in the next CBA.

Another rule that will be tested during this year’s Atlantic League season is moving the pitching rubber back one foot (60’6″ to 61’6″). This will provide batters more time to react to pitches.

MLB expects the change will help batters make contact more frequently, and thus, put more balls into play to create more action. A record 23.4% of plate appearances during the 2020 season resulted in strikeouts as pitchers gained more velocity through the use of technology.

The average fastball velocity was 93.3 mph last year from the normal mound distance. By moving the pitching rubber back one foot, MLB projects that would drop to 91.6 mph.

This change is expected to be meaningful and not pose an increased injury risk to pitchers.

Additional rules MLB is testing during 2021 Atlantic League season

Among other rules MLB will test during the 2021 Atlantic League season include upgrading the TrackMan tracking technology used to project and measure pitches.

The Atlantic League additionally will continue its use of the automated ball-strike system to assist the home plate umpire with calling balls and strikes.

The system has been improved this year to feature upgraded ball-tracking technology and modifications in order to better match the strike zone that players are familiar with.

Have you subscribed to the Dodger Blue YouTube channel? It’s the best way to watch player interviews, participate in our shows and giveaways, and more!