What one full year of the shift ban actually proved
Major League Baseball banned the shift in 2023 with a specific set of predictions in mind. Left-handed pull hitters who had been eaten alive by three-infielder right sides would see their batting averages on balls in play come back. Line drives up the middle would more often turn into hits. Strikeout rates would drop slightly because hitters would stop trying so hard to elevate over the shift. Offense would pick up. The pace of the game would improve as more balls went into play.
It's now been multiple full seasons since the rule went in. Some of those predictions were correct. Some were wrong. The most interesting result is the one nobody outside front offices predicted, which is that the league found ways to recover most of the defensive advantage the shift used to provide without technically violating the rule. The shift ban worked. The shift philosophy did not go away.
What the rule actually says
The shift ban requires four infielders, with two on each side of second base, both feet on the infield dirt at the moment the pitch is released. Outfielders can still be positioned wherever the defense wants. Infielders can rotate after the pitch — they can move once the ball is released — but the starting alignment must be conventional. The rule was designed to ban the most extreme shifts, where three infielders crowded the right side and a fourth was sometimes in shallow right field.
The rule was not designed to ban depth, positioning within each side of the field, or the use of analytics to set defensive starting points. All of those are still legal. The "shift" in the colloquial sense — the use of advanced positioning data to defend hitters where they actually hit the ball — survived the ban. What got banned was the specific topological move of overloading one side of the infield.
What the data showed in year one
Left-handed pull hitter batting average on balls in play recovered, as predicted. The cohort of hitters who had been most aggressively shifted in the prior era — left-handers with strong pull tendencies who didn't bunt and didn't try to slap the ball the other way — saw their BABIP climb by 20 to 30 points in the first year of the new rule. That's a meaningful improvement, more or less the level the rule's authors had modeled.
Overall league batting average rose slightly, but less than many of the rule's defenders had expected. The reason: the share of plate appearances that ended in shift-defensible ground balls was always a minority of all plate appearances. Most plate appearances end in strikeouts, walks, fly balls, or line drives over defenders' heads. The shift ban couldn't help any of those. It could only help the ground balls and short line drives that the shift was specifically designed to eat. That subset is real but it isn't the whole pie.
Strikeout rates did not drop. This was the prediction that didn't pan out. The hitters who had been swinging for elevated contact to beat the shift kept swinging for elevated contact after the shift was banned, because elevated contact produces home runs and home runs are worth more than singles. The underlying optimization was about extra-base power, not just the shift, and removing the shift didn't change the math on elevation. Several analysts published versions of this argument before the rule went in. They were correct.
What defenses did instead
Two adaptations, both subtle. The first is that infielders now play deeper than they used to. With one fewer fielder on the pull side of the infield, the players who are there need to cover more ground per fielder, and the way you cover more ground from a standing start is to begin closer to the action. The second baseman's average starting depth against pull hitters has crept back by several feet across most teams, and the shortstop's coverage of the right side from his nominally left-side position has gotten more aggressive in the post-pitch movement.
The second is that outfielders have moved. Outfield shifts were always legal — the rule applied only to infielders — and the teams that lost their infield shift advantage have responded by building more aggressive outfield positioning. The classic no-doubles depth, the four-outfielder alignments against extreme pull hitters, the shallow shading on weak contact hitters: all of these have grown. The fielded run-prevention is approximately the same as it was; the shape of it has just moved.
Public analyses of expected runs allowed per game show a small but persistent overall reduction in defensive efficiency since the ban, perhaps half a run per game across the league, but that gap is smaller than the gap the rule's authors anticipated. Most of the original advantage of the shift has been recovered via legal means.
What hitters did
Less than many expected. The argument for the shift ban was partly that it would unlock a generation of hitters who had been trained to hit through the shift via launch-angle elevation, and that those hitters would now revert to spraying the ball around the field. Mostly they haven't. The hitter who was already optimizing for an elevated, pulled-hard-contact approach in 2022 is still optimizing for that in 2026. The rule didn't change the underlying incentives. A homer is still worth more than a single.
A few players have made visible adjustments — the slap-hitting left-handed second baseman archetype is having a small revival, and a couple of veterans who had been over-aged out of starting roles got new contracts because their oppo-field skills were suddenly worth more — but the bulk of the league's offensive approach is unchanged. The launch-angle revolution outlived the shift it had originally responded to.
The pace effect
The other rule changes that came in alongside the shift ban — the pitch clock, the larger bases, the limit on pickoff attempts — have done more to change the game's pace and offensive output than the shift ban itself. Pitch-clock-era games are shorter, more action-packed, and produce more stolen bases than the pre-clock era. The pace improvements have come almost entirely from those rules. The shift ban contributed, but as a single-rule intervention it would not have moved the needle as far as the package did.
The general lesson
The shift ban is a case study in how sports rule changes interact with optimization. The rule banned a specific formation. It did not ban the analysis that produced the formation. Teams that had built whole defensive philosophies on data-driven positioning could not be made to forget the analysis; they just had to express it within the new constraints. The result is that the rule worked at the level of the rule and didn't fully work at the level of the underlying philosophy.
This pattern is familiar from other sports. Rule changes that try to undo the second-order effects of analytical optimization usually have to grapple with the fact that the analytical insight itself can't be banned. The NBA's defensive three-second rule was supposed to bring back interior post play; it mostly didn't, because spacing-and- shooting was a deeper philosophy than a single defensive positioning rule could repeal. Soccer's various back-pass rule tweaks didn't permanently change the way teams build out of the back. The shift ban joins a long list of well-intended rule changes that achieved their narrow goals and left the broader strategic landscape mostly intact.
The right read on the shift ban is not "it worked" or "it failed." Both claims have evidence behind them, and both are partially correct. The right read is that a single rule rarely undoes a decade of analytical adaptation, and that the league office's most effective tool isn't the rule itself but the steady accumulation of rules over time. The shift ban is one component of a multi-year project to remake the rhythm of baseball. Looked at on those terms, year one was about what you'd expect.