The Shift Restrictions Explained: Where Infielders Must Stand
Since 2023, major-league infielders must start every pitch with two on each side of second base and all four inside the infield boundary. Here is exactly what that allows, what it forbids and what changed.
Until the end of the 2022 season, a major-league manager could put his fielders anywhere he liked. He could move three infielders to one side of second base, station a second baseman in shallow right field, or park a shortstop in the outfield grass for a left-handed pull hitter. Beginning with the 2023 season, that freedom ended. Two infielders must stand on each side of second base, and all four must start the pitch inside the boundary of the infield. Everything else about defensive positioning remains the manager's choice.
The rule is short, but it raises a surprising number of practical questions. What counts as a side of second base? What does "inside the infield" mean when the infield has a grass portion? What happens when a team breaks the rule? And did the rule actually change the game? This article answers each question, gives examples of legal and illegal alignments, and looks at what the league-wide numbers did in 2022 and 2023. The season figures come from the historical record. The rule is described as it stood for the 2025 season, and anyone who needs the exact wording or an interpretation should check the official rulebook.
What the rule requires
The restriction has two parts, and both apply at the moment the pitcher releases the ball. The first is a count: two infielders must be positioned on the left side of second base and two on the right. The second is a location: all four infielders must have both feet within the outer boundary of the infield, which is the arc where the infield meets the outfield grass.
Both parts have to be satisfied at the same time. A team that keeps two men on each side of second base but puts one of them in the outfield grass has broken the depth rule. A team that keeps all four inside the arc but stacks three on one side has broken the side rule. Either violation is a violation.
The line that divides the sides is an imaginary one that runs from home plate through second base and out toward center field. The idea is simple: if you picture the field cut in half along the line from the plate to the middle of the diamond, each half needs two infielders.
The rule is also aimed at attempts to get around it by swapping fielders from one side to the other during a plate appearance. The precise limits on swapping positions are in the official text. Once the pitch is released, though, the restriction ends. A shortstop who starts in a legal spot can break toward the hole, and a second baseman can cut across the bag to cover a bunt. The rule governs where they start, not where they can go.
What it does not restrict
Many people assume the rule bans the shift altogether. It does not. A team can still move its fielders toward a hitter's pull side, as long as the two-and-two split and the infield boundary are respected. A second baseman can play deep in the hole between first and second. A shortstop can play on the grass behind the bag. A third baseman can play on the line or well off it. The fielders on the far side of the diamond can shade toward the middle. All of that is legal.
The rule does not say how deep inside the infield a fielder must stand. A middle infielder can play on the outfield edge of the dirt, as long as both feet are within the boundary. It also does not govern the pitcher and catcher, who are not counted among the four infielders, or the outfielders, who can still be placed anywhere the manager chooses. A team can play three outfielders in a straight line, shade them toward the pull side or bring one in close.
What the rule removes are the two extreme alignments that had become common. The first is the infielder in the outfield grass, such as a second baseman positioned in short right field against a left-handed hitter, a look that analytics departments had made routine. The second is the lopsided infield, in which three players stand on one side of the bag and only one covers the other side. Those looks are the ones that the rule makes illegal.
Legal and illegal alignments
Some examples show how it works. The table describes alignments for a left-handed pull hitter, the classic target of the shift.
| Alignment | Legal? | Why |
|---|---|---|
| Third baseman, shortstop and second baseman all on the right side of second base, first baseman also on the right | No | Three or more infielders on one side of second base |
| Second baseman plays in short right field, on the outfield grass | No | An infielder is outside the infield boundary |
| Third baseman and shortstop both on the left side of the bag but shaded toward the middle, second baseman deep in the hole, first baseman near the bag | Yes | Two on each side and all inside the arc |
| Second baseman plays deep behind the bag on the grass inside the arc | Yes | Inside the boundary, and the side count is still correct |
| Four infielders in the normal positions | Yes | Standard alignment |
| An infielder moves to a new spot after the pitch is released | Yes | The restriction ends at release |
The practical effect is that a defense can shade, but it cannot overload. The best a manager can do against a left-handed pull hitter is to shift each of the four players a few steps toward the right side, keeping two on each side of the bag. The old three-on-the-right look is gone.
What happens when a team breaks the rule
The umpires enforce the rule at the moment of the pitch. When the rule began in 2023, a violation brought an automatic ball added to the count, and the offense could choose to accept the result of the play instead. Before the 2025 season the league made the penalty harsher: if an illegally positioned infielder is the first to field the batted ball, the offense can take first base for the batter, with runners moving up one base, or accept the result of the play. The details of those options are in the official rules, and a fan should check them for the exact conditions.
The point of the penalty is to avoid rewarding a team for breaking the rule while avoiding the harsh result of taking away a hit. If a batter drives a ball into the gap against an illegal alignment and reaches base, the offense can simply accept the play and keep the hit. If an illegally placed fielder makes the out, the offense can take the free base instead. That design is similar to other rules in the sport that give the offense an option when the defense errs.
Because the penalty can cost a team a free base or a ball on the count, managers have a strong incentive to get the alignment right before every pitch. The violations that do occur come from the two things the rule is built around: a fielder on the wrong side of second base, or a fielder with a foot outside the infield boundary.
Where the shift came from
The shift is not a modern invention. One of the best-known early examples dates to 1946, when Cleveland manager Lou Boudreau moved his fielders to the right side of the field against Boston's Ted Williams, a left-handed pull hitter. That alignment, which was sometimes called the Williams shift, was a news story at the time because it was so unusual.
For decades after that it remained an occasional tactic used against a few extreme pull hitters. Then, in the early years of this century, clubs began collecting detailed data on where each batter hit the ball. When the data showed that some hitters put a very high share of their grounders and line drives into the same few zones, the shift became more common. By the 2010s it was routine against many left-handed hitters, and it spread to right-handed hitters as well. The rise of the shift went hand in hand with the rise of analytics departments in front offices, and it is one of the best examples of how data changed the way the game is played.
The practice had a cost for the sport. A hitter whom a defense had positioned against could lose a hit on a ball that would have been a single in a traditional alignment, and fans saw fewer groundball singles through the right side. League officials argued that the shift had reduced the amount of action in the game, and that argument became part of the case for the rule. Before adopting it in the major leagues, the league tested alignment restrictions in the minor leagues in the seasons before 2023, and the rule was announced as part of a package of changes that also included a pitch clock.
What changed in the numbers
The historical season sheets for 2022 and 2023 allow a before-and-after comparison, since 2022 was the last season without the restriction and 2023 was the first with it. The table gives the league-wide averages.
| Measure | 2022 | 2023 |
|---|---|---|
| Runs per team per game | 4.28 | 4.62 |
| Home runs per team per game | 1.07 | 1.21 |
| Strikeouts per team per game | 8.40 | 8.61 |
| Total attendance | 64,556,658 | 70,747,365 |
Runs per game rose by 0.34, from 4.28 to 4.62, a notable jump in one season. Home runs per game also rose, and strikeouts rose slightly. A fan might see those numbers and conclude that the shift restriction caused a surge in offense, but that conclusion would be a mistake.
The reason is that 2023 brought several rule changes at once. The league introduced the pitch clock, enlarged the bases and limited the number of times a pitcher could step off the rubber or throw over to a base. Each of those changes could affect offense. A larger base shortens the distance between bases, a pitch clock changes the pace of the game and pitchers' fatigue, and the pickoff limit makes stolen bases easier. Because they all started in the same year, the season totals cannot separate the shift rule's contribution from the others'.
The home-run increase, in particular, is unlikely to be a shift effect. A shift is a defensive alignment against balls on the ground and in the gaps. A ball hit over the fence does not care where the infielders stand. So the rise in home runs per game has other possible explanations, and these season totals cannot say which. The shift rule's effect would be expected to show up mainly in batting average on balls in play and in the number of ground-ball singles, and for those figures a reader should consult a dedicated statistics source.
For readers who want to see leaders in action, the batting leaders for 2022 and 2023 include left-handed contact hitters such as Arraez and McNeil. In 2022 Luis Arraez led the American League in batting at .316 and Jeff McNeil led the National League at .326. In 2023 Arraez led the National League at .354 and Yandy Diaz led the American League at .330. A single season of leaders does not prove an effect, and it is not offered as evidence; it only shows who the best hitters were in the two seasons on either side of the rule.
How managers adapted
Once the rule was in place, managers had to adjust. The extreme overshift went away, and in its place came subtler positioning. A second baseman might play a few steps deeper than normal in the hole on the right side, while the shortstop played on the grass behind second base. A third baseman might shade a few steps toward the middle. These alignments are legal, and they capture some of the benefit of the old shift.
A staff that had planned its defense around an extreme alignment had to rethink it, and the outfielders, who were not restricted, remained free to shade as far as the manager liked.
The skill of the fielders arguably matters more under the rule. A rangy shortstop who can reach balls in the hole is worth more when his manager cannot add a third player to that side of the bag, and the same is true of a third baseman who can cover the line. Evaluating those skills is hard, and the defensive metrics that try to measure range have limits of their own.
What it meant for pitchers
In principle, the rule matters most to pitchers who rely on ground balls. A pitcher who gets strikeouts or pop-ups is less affected, because those outcomes do not depend on the infield alignment. The distinction matters for fantasy players and for bettors, who sometimes assume a pitcher's results are a fixed property when they depend in part on the defense behind him.
For readers who follow betting markets, defensive changes of this kind are one input among many, and none of them guarantees a result. Gambling carries risk, is for adults of legal age where it is legal, and anyone worried about their betting can call 1-800-GAMBLER. An overview of the main bet types is in Moneyline, run line and totals explained.
Related rules that changed together
The shift restriction was part of a bundle. The pitch clock, described in the pitch clock in detail, limits the time between pitches. The bigger bases and the pickoff limit changed the running game. Together they were meant to speed up the pace of play and increase action on the field. If you want to see how a different rule change altered the game over time, the designated hitter rule's history and arguments is a good comparison, since the DH also changed who bats and how managers build a roster.
Two other rules fit alongside the alignment rule. When a runner is on third base, a fly ball in the outfield creates the possibility of a tag-up and a sacrifice fly, and tagging up and the sacrifice fly explains how that works. The difference between a force play and a tag play, which determines how an infielder must record an out, is covered in force plays and tag plays. Both are useful background for understanding what an infielder does after he fields a ball.
Common questions
Is the shift banned? No. Teams can still shade their fielders toward one side. The rule requires two infielders on each side of second base and all four inside the infield boundary.
When did the rule start? With the 2023 major-league season.
Does the rule say anything about outfielders? The rule is written around the four infielders. For how a particular unusual alignment is treated, such as a fifth fielder brought into the infield, check the official rulebook.
What if the defense breaks the rule? The penalty has been an automatic ball on the count with an option for the offense, and since 2025 a free base for the batter if the misplaced fielder is the first to field the ball. See the official rules for the exact terms.
Can the infielders move after the pitch? Yes. The restriction applies at the moment of release. After that, fielders can go anywhere.
Did the rule raise batting averages? The league-wide run totals rose in 2023, but several rules changed at the same time, so the figures here cannot isolate the effect of this one.
Where to go next
To follow how the sport's rules fit together, read the pitch clock in detail and the designated hitter's history, then browse the rules and umpiring topic page for current coverage. To see who led the league in a given year, use the leaders page.