Baseball Glossary › Left on Base
Left on Base (LOB)
LOB stands for left on base. For an individual batter it counts the runners still on base when he makes an out. For a team or a pitcher it counts the runners left on base at the end of each inning. LOB shows how many scoring chances went unused, which is why it is often called runners stranded.
What to Know
The two meanings produce different numbers. A batter who makes the last out with the bases loaded is charged with three LOB, and the team is also left with three that inning. But a batter who makes the first out with a runner on is charged with one even if a teammate later drives that runner in, so individual LOB totals do not add up to the team total.
Team LOB is part of the official box score: the Official Baseball Rules require the scorer to record the number of runners left on base by each team. It is a useful check on a team's chances with runners in scoring position.
LOB is circumstantial. A team that reaches base often will strand more runners simply because it has more of them, so a high LOB can come from a strong on-base percentage as much as from poor hitting in the clutch.
Frequently Asked Questions
What does LOB mean in baseball?
LOB stands for left on base. It counts runners who were stranded on base without scoring, either when a batter made an out (individual LOB) or when an inning ended (team or pitcher LOB).
How is LOB counted for a batter?
For an individual batter, LOB is the number of runners still on base when he makes an out. If he grounds out with runners on first and second, he is charged with leaving two on base.
What is team LOB in a box score?
Team LOB is the number of runners a team left on base at the end of each of its innings, added up for the game. The Official Baseball Rules require the official scorer to record it.
Why don't individual LOB totals add up to the team LOB?
Because they measure different moments. A batter is charged when he makes an out, even if a later hitter drives the runner in. Team LOB only counts runners still on base when the inning ends.
Is a high LOB bad?
Not always. A high LOB means runners were stranded, but teams that get on base often have more runners to strand. LOB is most useful alongside how often the team reached base and scored.
What does LOB mean for a pitcher?
For a pitcher, LOB counts the runners left on base at the end of the innings he pitched. Stranding runners is part of preventing runs, so pitchers who leave runners on base keep their run totals down.
Related Terms
Sources
- MLB.com Glossary: Left On Base (LOB)
- MLB.com Glossary: Plate Appearance (PA)
- Official Baseball Rules 2026 (MLB)
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