Major League Baseball Piloting Experimental Outfield Positioning Rules in Arizona Fall League

Major League Baseball is once again using the Arizona Fall League as a laboratory for potential rule changes at the major league level. In the past, the AFL has been a proving ground for rule alterations that have made their way to the top level of play, from the pitch timer, to limits on infield shifts, to the ABS challenge system; other initiatives, such as check swing challenges and fully automated balls and strikes, have previously been tested in Arizona but not implemented in the majors. This year, FanGraphs can report that the AFL is piloting new rules restricting defender positioning both on the infield (with the bases empty) and, perhaps more notably, in the outfield. Though MLB implemented restrictions on where infielders can play in 2023, this is the first time the league is piloting guard rails around where outfield defenders can be positioned when a pitch is thrown.
These restrictions first came to my attention during Monday’s game at Salt River Field, where Brendan Gawlowski and I noticed two things. First, Brendan noticed that the two teams’ corner outfielders were positioned both very close to the foul lines and much shallower than contemporary outfielders typically play. Of course, there are situations where a team might want to strategically align their outfielders like this, but for both teams to be doing so regardless of the hitter or game situation struck us as strange. Here is what that looked like on Monday:






