The independent Atlantic League, in order to receive certain benefits from Major League Baseball, agreed to serve as something of a playground for the rules experiments that were, perhaps, a little more extreme than whatever MLB might be willing to test at that time in affiliated leagues.
While that has included some things that wound up making their way to affiliated ball – shift limitations, larger bases, extra-innings runners, etc. – it also included one of the most extreme changes we’ve seen: increasing the mound distance an extra foot, to 61′ 6″. Unlike other changes that were met with skeptical acceptance, that one was never particularly popular, nor did the data bear out that it was getting the intended results (more balls in play, as batters should have a little more time to make contact).
So the league is dumping it. And robo umps, too, though that one seems to have been deemed a success, and thus is moving over to more usage in affiliated ball.
The Atlantic League has used the Automated Ball-Strike (ABS) system since the second half of its 2019 season and throughout the 2021 campaign as part of its innovative Test Rules and Equipment Partnership with Major League Baseball (MLB). Following the ALPB experiment and assessment, ABS is moving to an MLB affiliated league.
Atlantic League pitching rubber distances were moved back one foot to 61’6” for the second half of the 2021 season as part of the MLB test rules partnership. The test proved inconclusive, so both parties agreed to restore the pitching rubber distance to its traditional length of 60’6” for the upcoming ALPB season.
I don’t foresee the increased mound distance coming to affiliated ball any time soon, so if it was deemed “inconclusive” in the Atlantic League and then dumped after a half-season, I’m thinking we probably won’t see it anywhere at all. The sacred 100+ year-old distance remains.
As for other rules changes, the Atlantic League announcement confirms that it will continue to partner with MLB on prospective changes. More will be announced this spring, presumably once the CBA is finalized, and MLB might have a better sense on some rules it might want to try out.
Otherwise, the big question is where robo umps wind up this year (all of A-ball? some of Double-A?), whether last year’s affiliated rules changes – pitch clock, larger bases, limited shift, and limited pick-offs – will live or die or change level.