Not that this thread gets much traction, but MLB is experimenting with player positioning again. Per FanGraphs:
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.
My sources indicated to me that the league’s motivation is to see if further limiting the locations where defenders are allowed to stand will create more base-hit action and have a positive impact on the game’s aesthetics.
Dark green hash marks have been painted on the outfield grass and at points along the arc where the infield dirt meets the outfield grass. Defenders have to stand within a certain distance of these hash marks when a pitch is thrown. Think of it like tape on the floor on the stage at your high school’s production of Little Shop of Horrors, indicating where the actors should stand to be in their best light.
These restrictions only apply to infielders when the bases are empty, but they apply to outfielders at all times.
In this alignment, infielders are forced to play “straight up,” while the corner outfielders are closer to the foul lines, and the center fielder is more shallow compared to where we see big league outfielders normally play nowadays.
If a player is positioned in compliance with the restriction, there is a green “O” visible as their marker. When they’re in danger of leaving the designated location, it shows an orange line, while a red “X” is visible when they’re no longer in compliance.
Penalties for non-compliance are enforced by the field umpires, who can see the LED board from their vantage points. For infielders, non-compliance will only result in a violation if the out-of-place defender is the one who fielded the ball in play; where the runner is placed is then a matter of umpire discretion, though first base seems the most likely spot. In the event a play is made by an outfielder who is outside the allowed radius, how many bases a batter is awarded is again a matter of umpire discretion, similar to the way fan interference is assessed.
Eliminating infield shifts hasn’t had the desired effect on the rate at which balls in play fall in for hits. Historically, the league-wide batting average on balls in play had hovered around .300, but since 2020, that number has shifted down to about .290 or so (it was .290 in 2026). As Russell Carleton has noted for Baseball Prospectus, the combination of lift-obsessed hitters and teams’ ability to use ball-in-play data to strategically position their outfielders, especially moving them deeper to limit the number of extra-base hits they surrender, has resulted in the BABIP environment we’re currently experiencing.