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Extra innings in Major League Baseball work differently in the regular season than they do in the postseason.
During the regular season, every half-inning beginning with the 10th inning starts with an automatic runner on second base. The rule is designed to increase the chance of scoring and reduce extremely long regular-season games.
During the postseason, there is no automatic runner. Extra innings begin with the bases empty, just as they did under traditional MLB rules.
The automatic-runner rule was first introduced in MLB during the shortened 2020 season and became a permanent regular-season rule in 2023.
Here is how it works and what it changes.
What Is the MLB Extra-Inning Rule?
If a regular-season game is tied after nine innings, each team begins its half of the 10th inning with a runner already on second base.
The same procedure continues in the 11th inning and every additional extra inning until the game ends.
The runner does not reach second because of a hit, walk, error or stolen base. The runner is placed there automatically under MLB rules.
You may hear fans call this player the:
- Automatic runner
- Placed runner
- Ghost runner
- Zombie runner
“Automatic runner” or “placed runner” is generally the clearest terminology when explaining the rule.
Who Starts on Second Base in Extra Innings?
The automatic runner is normally the player in the batting order immediately preceding the batter who leads off the inning.
For example, imagine the No. 5 hitter is scheduled to lead off the 10th inning.
The No. 4 spot in the batting order would normally supply the automatic runner at second base.
A team can substitute for that player under normal substitution rules, including using a pinch-runner.
This creates an immediate strategic decision. A manager may prefer a faster runner at second, but making the substitution can affect the team’s lineup and available bench players later in the game.
Does the Automatic Runner Count as an Earned Run?
If the automatic runner scores, the run counts on the scoreboard but is generally not charged as an earned run to the pitcher.
For earned-run accounting, the placed runner is treated as though the runner reached second because of a fielding error.
Consider this example:
The 10th inning begins with an automatic runner on second.
The pitcher retires the first two hitters, but the third hitter singles and the automatic runner scores.
The team scores a run, but that run is unearned against the pitcher.
This prevents a pitcher from having his ERA increased simply because MLB placed a runner in scoring position before the pitcher threw a pitch.
Does the MLB Postseason Use the Automatic Runner?
No.
This is one of the most important differences between regular-season and postseason baseball.
During the regular season:
10th inning → automatic runner on second
During the postseason:
10th inning → bases empty
Postseason games continue under traditional extra-inning rules until one team wins.
So a playoff game can still extend deep into extra innings without MLB automatically placing a runner on second.
When Did MLB Introduce the Automatic Runner?
MLB first introduced the automatic runner during the 2020 season.
The rule initially appeared as part of a group of temporary measures during the pandemic-shortened season.
MLB continued using it during subsequent regular seasons.
In 2023, the Joint Competition Committee voted to make the automatic-runner rule permanent for regular-season games.
That distinction matters because older articles sometimes still describe the rule as temporary or experimental.
It is no longer a temporary MLB regular-season experiment.
Why Does MLB Use an Automatic Runner?
The most obvious effect is that teams begin every extra inning with a runner already in scoring position.
That increases the possibility that the game will be decided earlier in extra innings rather than continuing for many additional frames.
It can also reduce the strain extremely long games place on pitching staffs.
Before the automatic-runner era, a long extra-inning game could force teams deep into their bullpens and occasionally into unusual pitching situations.
The current format creates immediate scoring pressure instead.
How Does the Automatic Runner Change Strategy?
The biggest strategic change is simple:
Every extra inning begins with a runner in scoring position and nobody out.
That makes the first plate appearance unusually important.
Visiting Team
The visiting team bats first and cannot know how many runs the home team will score in the bottom half.
Scoring one run gives it the lead, but the home team will also begin its half-inning with a runner on second.
That can make playing for multiple runs attractive.
Home Team
The home team’s strategy depends heavily on what happened in the top half.
If the visiting team fails to score, the home team needs only one run to win.
In that situation, advancing the automatic runner to third can become especially valuable because a sacrifice fly, hit or certain defensive mistakes could end the game.
If the visiting team scores multiple runs, the home team’s approach changes because simply advancing one runner is no longer enough.
Should Teams Bunt in Extra Innings?
The automatic runner makes sacrifice bunting more relevant, but bunting is not automatically the correct strategy.
Suppose the home team begins the bottom of the 10th in a tie game.
A successful sacrifice bunt could create:
Runner on third + one out
The home team could then win on several types of plays.
But the bunt also gives the defense an out.
With a strong hitter at the plate, a manager may prefer to let the hitter swing rather than sacrifice an out.
The decision depends on factors such as:
- Score
- Batter quality
- Runner speed
- Pitcher matchup
- Number of outs
- Available bench players
The automatic runner therefore changes the strategic environment without creating one universally correct approach.
Can Teams Use a Pinch-Runner for the Automatic Runner?
Yes.
A manager can substitute another eligible player for the automatic runner under MLB’s normal substitution rules.
For example, a slower player might be due to start the inning at second base. The manager could replace that player with a faster pinch-runner.
But there is a cost.
Once the original player has been removed from the game, that player generally cannot return.
Managers therefore have to balance the immediate value of speed against the possibility that the game continues for several more innings.
What Happens to the Batting Order?
The batting order does not reset or change because of the automatic runner.
The next scheduled hitter still leads off the inning.
The automatic runner is simply placed on second before that plate appearance begins.
For example:
No. 7 hitter made the previous plate appearance that completed the prior inning.
No. 8 hitter is scheduled to lead off the 10th.
The player occupying the No. 7 batting-order position would normally begin the inning on second.
The No. 8 hitter still comes to the plate.
How Does ABS Work in Extra Innings in 2026?
There is one important new wrinkle for 2026.
MLB introduced the Automated Ball-Strike (ABS) Challenge System, which allows eligible players to challenge certain ball-strike calls.
Each team normally begins a game with two ABS challenges.
If a team reaches an extra inning with zero ABS challenges remaining, MLB gives that team one ABS challenge for the inning.
If the game continues and the team again begins the next extra inning with no challenges, it receives another one.
This rule is separate from the automatic runner.
So beginning in 2026, extra innings can involve two special mechanisms at the same time:
Automatic runner on second + extra-inning ABS challenge provision
Does the Pitch Clock Still Apply in Extra Innings?
Yes.
MLB’s pitch-timer and disengagement rules continue to apply during extra innings.
The automatic runner does not suspend the normal pace-of-play rules simply because the game has gone beyond nine innings.
That means pitchers, hitters and baserunners still operate under the same pitch-timer framework used during regulation innings.
Regular Season vs. Postseason Extra Innings
The easiest way to remember the rules is:
| Rule | Regular Season | Postseason |
|---|---|---|
| Extra innings begin after | 9 innings | 9 innings |
| Automatic runner on second | Yes | No |
| Starts in | 10th inning | Not used |
| Continues in later extras | Yes | Not applicable |
| Normal batting order continues | Yes | Yes |
| Game can end in a tie | No | No |
| ABS Challenge System in 2026 | Yes | Yes |
The major difference is the automatic runner.
MLB uses it to accelerate regular-season extra innings while preserving traditional bases-empty extra innings during the postseason.
Example: How a 10th Inning Works
Imagine a regular-season game is tied 3-3 after nine innings.
Top of the 10th
The visiting team begins with an automatic runner on second.
The first hitter grounds out, moving the runner to third.
The next hitter hits a sacrifice fly.
The runner scores.
The visiting team now leads 4-3.
Bottom of the 10th
The home team also begins with its automatic runner on second.
A single scores the runner.
The game is tied 4-4 again.
If the home team does not score another run, the game proceeds to the 11th inning.
Both teams again begin their half of the 11th with an automatic runner on second.
This continues until one team finishes an inning with the lead after the home team’s opportunity to bat.
Frequently Asked Questions
When does the automatic runner start in MLB?
The automatic runner begins in the 10th inning of regular-season games and continues in every additional extra inning.
Who is the automatic runner?
Normally, it is the player in the batting order immediately preceding the hitter scheduled to lead off the inning.
Can the automatic runner be replaced?
Yes. A manager can use an eligible substitute as a pinch-runner under normal substitution rules.
Is an automatic runner’s run earned?
Generally no. For earned-run purposes, the automatic runner is treated as though the runner reached second because of an error.
Does MLB use the ghost runner in the playoffs?
No. MLB postseason extra innings begin with the bases empty.
Is the automatic-runner rule temporary?
No. MLB made the regular-season automatic-runner rule permanent beginning in 2023.
Do teams get another ABS challenge in extra innings?
If a team begins an extra inning with no ABS challenges remaining, it receives one challenge for that inning under the 2026 ABS rules.
Final Answer
In MLB regular-season games, every half-inning beginning with the 10th inning starts with an automatic runner on second base.
The runner is normally the player in the batting order immediately before the inning’s leadoff hitter. If the placed runner scores, the run counts but generally does not count as an earned run against the pitcher.
The rule became permanent for the regular season in 2023.
The postseason is different: there is no automatic runner, and extra innings begin with the bases empty.
Beginning in 2026, teams that enter an extra inning without an ABS challenge also receive an extra-inning ABS challenge, adding another strategic element to MLB’s modern extra-inning rules.