Baseball innings explained
How many innings are in a baseball game? Nine-inning MLB rules explained
An MLB game is scheduled for nine innings. Each inning has a top half and a bottom half, and each team gets three outs while batting. A game can end after the top of the ninth when the home team leads, end during the bottom half on a walk-off, go past nine when tied, or finish early under MLB's regulation-game rules.
Sources and resources
- Official MLB regulation-game glossary — MLB's explanation of nine innings, 27 outs, early endings, weather, and extra innings.
- Official MLB automatic-runner rule — MLB's rule for starting each regular-season extra half-inning with a runner on second base.
- Official MLB definition of an out — MLB's explanation that three outs retire the batting side in an inning.
- Official 2026 MLB rules index — MLB's current rules index and link to the complete 2026 Official Baseball Rules.
How many innings are in an MLB game?
A regulation MLB game is scheduled for nine innings. The visiting team bats in the top half of each inning, and the home team bats in the bottom half.
Each batting side gets three outs before the teams switch roles. Nine full innings can therefore contain 18 half-innings and 54 outs, though the game often ends before every possible out is recorded.
- Nine scheduled innings.
- Two halves in each inning: top and bottom.
- Three outs for each batting team per half-inning.
Why can a nine-inning game end after eight and a half innings?
If the home team leads after the visitors make three outs in the top of the ninth, the home team has already won. It does not bat in the bottom of the ninth.
People often call this eight and a half innings because only the top half of the ninth was played. MLB still treats it as a completed regulation game.
What is a walk-off ending?
When the home team takes the lead in the bottom of the ninth or a later inning, the game ends at once. The visitors have no later turn at bat, so the winning half-inning can stop before three outs.
A walk, hit, sacrifice fly, error, wild pitch, or home run can produce the winning run. The way the run scores changes the box score, but not the rule that the game ends when the home team moves ahead.
What happens when the score is tied after nine innings?
A tied MLB game continues into extra innings. There is no fixed cap: the teams keep playing until one side wins under the normal end-of-game rules.
In the regular season, each half-inning after the ninth starts with an automatic runner on second base. The runner is meant to help settle the game sooner and does not count as an earned run if he scores.
- The 10th inning is the first extra inning.
- Both teams get a turn unless the home team takes the lead first.
- Regular-season extra half-innings begin with a runner on second.
Are postseason extra innings different?
Yes. MLB postseason games can also continue past nine innings, but each extra half-inning starts with the bases empty. The regular-season automatic runner is not used in the playoffs.
A postseason game keeps going until the visiting team holds a lead after a completed inning or the home team scores the winning run.
Can an MLB game end before nine innings?
Yes. Weather or another interruption can shorten a game. MLB considers a game regulation once the visiting team has made 15 outs and the home team leads, or once the home team has made 15 outs regardless of the score.
Reaching that point does not mean every interrupted game is final. The score, timing of the interruption, and suspension rules determine whether MLB records a final result or resumes the game later.
Do all baseball games have nine innings?
No. Nine innings is the MLB standard, but other leagues can use different game lengths. Youth baseball, school baseball, amateur tournaments, Minor League doubleheaders, and softball may follow seven-inning, six-inning, time-limit, or mercy-rule formats.
Check the rules for the league and event you are watching. This guide describes current Major League Baseball games.
Keep the ending you witnessed
The final score shows who won, but the inning tells you how the game felt: a routine top-of-the-ninth finish, a walk-off, a rain-shortened result, or a long night in extras.
Log the completed game in Gamebook with its final score, ballpark, section, row, seat, players, home runs, companions, photos, and memory. It becomes part of your team record, ballpark passport, and lifetime baseball history.
Common questions
How many innings are in a baseball game?
A regulation MLB game is scheduled for nine innings. Other baseball leagues can use shorter formats, so check the rules for the level you are watching.
How many outs are in a nine-inning baseball game?
Nine complete innings can contain 54 outs: three outs for each team in each inning. A game can end with fewer outs when the home team leads after the top of the ninth or wins on a walk-off.
Why is a baseball game sometimes only eight and a half innings?
If the home team leads after the top of the ninth, it does not need to bat again. The game ends even though the bottom of the ninth was not played.
What happens if an MLB game is tied after nine innings?
The game goes to extra innings and continues until one team wins. Regular-season extra half-innings start with an automatic runner on second base.
Is there a limit to extra innings in MLB?
No. MLB games have no fixed extra-inning cap. Play continues until the visiting team leads after a completed inning or the home team scores the winning run.
Does MLB use the automatic runner in the playoffs?
No. Postseason extra innings start with empty bases. The automatic runner on second is a regular-season rule.
How many innings make an MLB game official?
A game reaches regulation status after five innings, or after four and a half when the home team leads. Interruption and suspension rules still determine whether the result is final or play resumes later.
How can I track a baseball game I attended?
Log the completed game in Gamebook with its final score, ending, ballpark, seat, players, home runs, companions, photos, and memory.