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MLB announces new rules for the minor leagues, including an anti-shift change

(Jonathan Newton /The Washington Post)

As part of a years-long effort to improve the pace of play and prevalence of action, MLB announced experimental rule changes will be implemented at each level of the minors this season.

The most eye-catching of the regulations will require Class AA teams to play four infielders on the infield dirt at all times, a clear effort to prevent the kind of extreme, data-driven shifts that have emerged as a prominent but polarizing strategy in recent years.

According to a news release announcing the decision, MLB might add another twist to the rule in the second half of the season: requiring two infielders to be positioned on either side of second base, effectively eliminating extreme shifting of any kind in an effort to “increase the batting average on balls in play.”

Changes at other levels include increasing base size from 15 inches square to 18 inches square at the Class AAA level in an effort to increase stolen base percentage and the likelihood of infield hits.

When MLB took control of and restructured the minor league system before the 2021 season, one of the advantages it cited was the ability to experiment. In the past, MLB partnered with the independent Atlantic League to try out changes, meaning unaffiliated teams were the only ones testing new ideas.

This year, MLB is using all four levels of its restructured player development system to experiment with changes “aimed at creating more action and improving the pace of play,” Michael Hill, MLB senior vice president of on-field operations, said in a statement Thursday.

Each level of the minors was given one big change in an effort to limit the variables and allow MLB to assess the impact. Increasing base size was considered the least invasive of the changes, so MLB decided to implement that at Class AAA.

While the shift change may be most discussed in the midst of a years-long conversation about whether the game is better off with defensive shifts or without, the rule testing at Class High-A sites almost certainly will rankle pitchers more. On an experimental basis, pitchers at that level will be required to “disengage the rubber prior to throwing to any base.”

For years, right-handed pitchers have come to a set position, sneaked a peek the runner on first, then pivoted to throw over. Left-handed pitchers, meanwhile, were able to keep their back foot on the rubber, set their eyes homeward, then throw over to first in an attempt to surprise a runner.

Now even left-handed pitchers will have to step off first, at least in Class High-A games, an experiment MLB hopes will increase stolen base attempts and percentage — in other words, increase action. When the Atlantic League tried this rule in 2019, stolen base attempts skyrocketed.

Many of MLB’s most data-driven teams don’t emphasize stolen bases as a part of their strategy. Simply put, they believe the risk of losing a base runner is not worth the reward. But if the stolen base percentage grows, those calculations may change.

At the same time, MLB is hoping to limit the number of pickoff attempts per batter with rules it will test at the Class Low-A level. To begin the season, Class Low-A pitchers will be allowed two “step offs” or pickoff attempts per batter. Depending on the impact of that change, MLB may decide to reduce the allotment to one in the second half.

“The game on the field is constantly evolving, and MLB must be thoughtful and intentional about progressing toward the very best version of baseball — a version that is true to its essence and has enough consistent action and athleticism on display to entertain fans of all ages,” Theo Epstein, the former general manager of the Boston Red Sox and former president of baseball operations for the Chicago Cubs, said in a statement. Epstein has publicly lamented changes he says data-driven front offices have made that result in a less appealing kind of gameplay and was hired by MLB to help improve on-field quality.

“These rules experiments will provide valuable insight into various ways to create a playing environment that encourages the most entertaining version of the game. What we learn in the Minor Leagues this year will be essential in helping all parties chart the right path forward for baseball.”

Other experiments will include the limited use of “robo umps” — the Automatic Ball-Strike system — at games in the newly organized Class Low-A Southeast Division. More stringent on-field timers will be implemented in Class Low-A West stadiums to limit time between innings and pitches.

Some changes tested in the minors have made their way to the major league level, most recently the rule putting a runner on second to begin each extra inning, the merits of which are still being debated. Many of these developments — particularly the one that could change the trajectory of defensive strategizing all together — could cause an even greater impact on the way baseball is played.