The 2021 minor league season will see some new and altered rules at the various levels of playing, according to a statement from Major League Baseball. “Consistent with the preferences of our fans, the rule changes being tested are designed to increase action on the basepaths, create more balls in play, improve the pace and length of games, and reduce player injuries,” the statement reads.
Many of these changes have long been discussed or even already used in other minor leagues — Baseball America’s J.J. Cooper notes that fans of the independent Atlantic League will recognize many of these rules adjustments. It also isn’t necessarily the case that all of these new rules (whether in their current form or whatsoever) will ever appear at the MLB level, given the trial-and-error basis.
Triple-A baseball will see the size of the bases increased from 15 inches square to 18 inches square, a deceptively minor change that could end up having a notable impact on a game. As the league’s statement reads, “the Competition Committee also expects the shorter distances between bases created by increased size to have a modest impact on the success rate of stolen base attempts and the frequency with which a batter-runner reaches base on groundballs and bunt attempts.” In addition, larger bases will also reduce the chances of collisions on the basepaths.
Double-A baseball will experiment with a new rule that addresses defensive shifts, since going forward, “the defensive team must have a minimum of four players on the infield, each of whom must have both feet completely in front of the outer boundary of the infield dirt.” While shifting has been part of baseball for decades, teams have been using shifts more often and in a more elaborate fashion over the last few seasons, to the point that seeing a club deploy four or even five players in outfield for a particular batter isn’t out of the ordinary.
This initial rule will keep infielders within the infield, and the statement also hinted at further limitations to shifts in the second half of the Double-A season: “Depending on the preliminary results of this experimental rule change, MLB may require two infielders to be positioned entirely on each side of second base….These restrictions on defensive positioning are intended to increase the batting average on balls in play.”
Step-off and pickoff moves are the primary focus of the Single-A rules changes, as in High-A ball, “pitchers are required to disengage the rubber prior to throwing to any base, with the penalty of a balk in the event the pitcher fails to comply.” This was one of the rules instituted in the Atlantic League in 2019, as noted in MLB’s statement, and the altered rule “resulted in a significant increase in stolen base attempts and an improved success rate.”
The step-off/pickoff rules will be even more significantly changed for all Low-A leagues. If there is one or more runner on base, pitchers can only throw a maximum of two pickoffs or make two step-offs per plate appearance. The pitcher can attempt a third pickoff or step-off but the play must result in the baserunner being retired. If the runner gets back to his original base on this third pitcher try, the play is called a balk and the runner advances anyway. MLB’s statement said that the limitation could be further lowered to just a single step-off or pickoff attempt per plate appearance, seeing how the initial rule plays out.
The Low-A West league will adopt on-field timers “to enforce time limits between delivery of pitches, inning breaks and pitching changes.” An even more interesting electronic element will be part of the Low-A Southeast league, as the Automatic Ball-Strike System will be used “to assist home plate umpires with calling balls and strikes, ensure a consistent strike zone is called, and determine the optimal strike zone for the system.”