The designated hitter rule has long been one of the defining—and most debated—features in Major League Baseball. Initially introduced in the American League, it created a fundamental difference in how the two leagues operated. But in 2022, the MLB unified both leagues under a single set of rules, making the designated hitter (DH) a permanent fixture across the board.
Here’s how the rule works today, why it exists, and how it continues to impact the game.
The designated hitter is a player in the lineup who bats in place of the pitcher but does not play a defensive position in the field. This allows teams to keep stronger hitters in the lineup while giving pitchers a break from having to bat.
The DH is typically slotted somewhere in the middle of the batting order and is often used to maximize offense without compromising the pitching staff’s effectiveness.
Under the current rules, the DH can only hit for one player per game, and that player is almost always the starting pitcher.
The designated hitter was first introduced by the American League in 1973, as a way to boost offensive production and increase fan engagement. Pitchers, generally poor hitters, were seen as an automatic out at the plate. The rule allowed teams to keep a more dangerous bat in the lineup without risking a pitcher at the plate or on the bases.
The National League resisted the change for decades, maintaining a more traditional approach where pitchers batted for themselves. This led to a persistent difference in strategy between the two leagues—particularly visible in interleague play and the World Series, where teams had to adjust based on whether the DH was in effect.
In 2022, Major League Baseball made the DH rule universal, applying it to both leagues and ending the split that had defined AL vs. NL strategy for nearly 50 years.
Once a designated hitter is listed in the lineup, that player must hit for the pitcher throughout the game, unless substitutions or double switches change the situation. A few key points:
The rule gives teams more flexibility with their lineup construction and opens up roles for power hitters who may not offer much defensively but still bring value at the plate.
With the DH, managers no longer have to consider the pitcher’s spot in the batting order when deciding when to make a pitching change. In the past, a pitcher performing well might still be pulled for a pinch hitter in late innings of a close game. Now, pitchers can go deeper without that added layer of decision-making.
It also reduces the use of complex substitution strategies like double switches, which were more common in NL games.
On the flip side, the DH adds a layer of offensive firepower, especially for teams with depth. It also allows veteran players to extend their careers by focusing solely on hitting, without needing to contribute defensively.
When the universal DH was announced, opinions were mixed. Traditionalists viewed it as the loss of a unique strategic wrinkle, while others welcomed the added offense and consistency.
Since its adoption, the universal DH has become an accepted part of the game. Teams have adapted quickly, and fans have seen an uptick in offensive production—exactly what the rule was originally intended to bring.
Designated hitters are now treated as full-time roster pieces, and clubs build around them in both free agency and player development.
The designated hitter rule has fundamentally changed how baseball is played and managed at the highest level. What started as an experiment in one league is now a universal standard across Major League Baseball.
Understanding how the DH functions helps explain why rosters look the way they do, how managers make in-game decisions, and why certain players—who may not take the field—can still play a huge role in a team’s success.
