Baseball Stats
What Does LOB Mean
What Does LOB Mean
in Baseball?
LOB stands for Left on Base — the runners who reached base but didn't score. Here's what it means, how it's calculated, and why it matters for hitters and pitchers.
⚡ Quick Answer
LOB stands for
Left on Base — the number of baserunners who don't score and remain stranded when an inning ends.
Team LOB
Total runners left on base across a game. MLB teams average 6–7 LOB per game.
LOB% (pitchers)
The percentage of baserunners a pitcher strands. MLB average is around 72%. Higher is better for pitchers.
Good LOB?
For teams — lower is better (fewer runners stranded means more runs scored). For pitchers — higher LOB% is better.
On the scoreboard
LOB appears in the box score alongside R (runs), H (hits), and E (errors). Modern scoreboards also show MVR (mound visits remaining) and ABS (automated ball-strike challenges, new in 2026).
What does LOB mean in baseball?
LOB stands for Left on Base. When an inning ends — either by three outs or, in rare cases, by the home team scoring the winning run in a walk-off — any runners still standing on base are counted as left on base. They reached base but didn't score.
It shows up two ways in baseball stats. As a raw count in the box score, it tells you how many baserunners a team stranded in a game. As a percentage (LOB%), it tells you what share of a pitcher's baserunners were stranded without scoring.
LOB = Total Baserunners − Runs Scored − Batters Left on Base via Double Play
Example: A team has 6 baserunners in an inning and 3 score.
LOB = 6 − 3 = 3 runners left on base
LOB = 6 − 3 = 3 runners left on base
6–7
Average MLB team LOB per game — roughly one per inning where runners reach base
72%
MLB average pitcher LOB% — the baseline for evaluating stranding ability
20
Most runners LOB by one team in a 9-inning game — NY Yankees, September 21, 1956
LOB on the scoreboard — what are you looking at?
If you have stared at a baseball scoreboard wondering what all those letters mean, here is the full breakdown. The standard line score shows runs, hits, and errors. The box score adds LOB plus a few others you will see on modern MLB scoreboards.
Standard MLB Box Score
1
2
3
4
5
6
7
8
9
R
H
E
LOB
Visitors
0
2
0
1
0
0
0
1
0
4
9
1
7
Home
1
0
0
3
0
1
0
0
X
5
8
0
5
What do all the letters on a baseball scoreboard mean?
Every letter and abbreviation you see on a baseball scoreboard has a specific meaning. Here is the complete reference including the two new additions you will see starting in the 2026 season.
| Letter | Stands For | What It Means |
|---|---|---|
| R | Runs | Total runs scored by each team |
| H | Hits | Total hits recorded by each team |
| E | Errors | Defensive errors committed by each team |
| LOB | Left on Base | Runners stranded on base when each half-inning ended |
| BB | Bases on Balls | Walks issued by each team's pitchers |
| SO / K | Strikeouts | Strikeouts recorded by each team's pitchers |
| HR | Home Runs | Home runs hit by each team |
| DP | Double Play | Double plays turned by each team's defense |
| SB | Stolen Bases | Bases stolen by each team's runners |
| CS | Caught Stealing | Baserunners caught trying to steal a base |
| WP | Wild Pitch | Pitches that get away from the catcher allowing runners to advance |
| PB | Passed Ball | Catcher's failure to catch a catchable pitch allowing runners to advance |
| MVR | Mound Visits Remaining | Each team gets 5 mound visits per 9 innings — tracks how many remain |
| ABS | Automated Ball-Strike | 🆕 New 2026 — each team gets 2 challenges per game to dispute a ball or strike call using the automated tracking system |
📊 MVR and ABS — the two you didn't know
MVR (Mound Visits Remaining) — introduced in 2018, each team gets 5 mound visits per 9 innings plus one extra per extra inning. Once they are used the pitcher must face the next batter. ABS (Automated Ball-Strike challenges) — new in 2026, each team starts with 2 challenges. A successful challenge is retained. An unsuccessful one is lost. Teams get one additional challenge per extra inning if both have been used.
What is a good LOB in baseball?
The answer depends on whether you are looking at it from an offensive or pitching perspective — because a good LOB number is the opposite for hitters and pitchers.
For teams / hitters — lower is better
Fewer runners left on base means more runs scored. MLB teams average 6–7 LOB per game. A team consistently under 5 is converting opportunities efficiently. A team regularly at 8 or above is leaving runs on the table.
For pitchers — higher LOB% is better
A pitcher's LOB% measures what percentage of baserunners they strand. The MLB average is around 72%. Pitchers above 75% are strong in high-leverage situations. Below 68% suggests they struggle to escape jams.
LOB for hitters — what it tells you
LOB is used to evaluate a hitter's situational hitting — their ability to drive in runners when it counts. A batter who consistently leaves runners in scoring position is failing in the situations that matter most.
That said, LOB as a solo stat is imperfect. A few reasons why:
It ignores no-runner situations
A hitter who gets on base a lot but never has runners ahead of them will naturally have a low LOB — not because they're clutch, but because they're often the first one on.
Defense and baserunning affect it
A batter can hit a ball hard with runners on base and still have a LOB tick up if the defense makes a great play or a baserunner gets thrown out trying to advance.
Sacrifice plays hurt the number
A batter who bunts a runner to third to set up a scoring opportunity will see their LOB percentage increase even if the next batter drives in the run. It is a team game and individual LOB does not capture that.
Walk-off wins create false LOB
Bases loaded, tie game, walk-off single scores the runner from third — game over. The two runners left on first and second count as LOB even though the game was just won. It is the clearest example of why raw LOB has limits.
LOB% for pitchers
For pitchers, LOB% (Left on Base Percentage) is a more meaningful version of the stat. It measures the percentage of baserunners a pitcher strands over the course of a season.
LOB% = (H + BB + HBP − R) ÷ (H + BB + HBP − 1.4 × HR)
MLB league average LOB% is approximately 72%. Elite relievers and high-strikeout starters typically exceed 75%.
High-strikeout pitchers generally carry higher LOB% because they can pitch their way out of jams without relying on the defense. A pitcher with a LOB% significantly above 75% over a full season may be due for regression — they are likely benefiting from favorable sequencing that tends to normalize over time. Conversely, a pitcher with an ERA higher than their underlying stats suggest is often carrying an abnormally low LOB%.
⚠️ LOB% and ERA regression
LOB% is one of the best indicators of future ERA movement. A pitcher with a LOB% well above 75% is likely to see their ERA rise. A pitcher with a LOB% well below 68% is likely to see improvement. When a pitcher's ERA and FIP are far apart, LOB% is usually the explanation.
LOB in softball stats
LOB means exactly the same thing in softball as it does in baseball — runners who reached base but didn't score when the inning ended. The stat appears in softball box scores at every level from youth rec leagues to college softball to Olympic competition. LOB% for pitchers is tracked the same way in softball, with similar league averages to baseball.
MLB LOB records
20
Most LOB by one team in a 9-inning game
New York Yankees — September 21, 1956. Twenty runners left on base and still lost. A masterclass in offensive inefficiency.
14
Most LOB by one player in a game
Ryan Zimmerman — August 5, 2016. A 13-inning game. Zimmerman stranded 14 runners across the marathon contest.
13
Second most LOB by one player in a game
Dustin Pedroia — September 15, 2017. A 15-inning game. Pedroia had 13 LOB across the longest game of his career.
94.4%
Highest single-season LOB% by a starting pitcher
Babe Adams — 1920. Adams stranded 94.4% of all baserunners he allowed across the entire season, the highest mark in MLB history since 1901.
Frequently asked questions
What does LOB mean in baseball?
LOB stands for Left on Base. It counts the number of baserunners who reach base but don't score — they're stranded when the inning ends. It appears in the box score and measures offensive efficiency for teams and stranding ability for pitchers.
What does LOB stand for in baseball stats?
LOB stands for Left on Base. In the box score it shows the total runners stranded by each team. For pitchers, LOB% (Left on Base Percentage) measures what percentage of baserunners allowed were stranded without scoring.
What is a good LOB in baseball?
For teams and hitters, lower LOB is better — fewer stranded runners means more runs scored. MLB teams average 6–7 LOB per game. For pitchers, higher LOB% is better. The MLB average pitcher LOB% is around 72%. Above 75% is strong; below 68% suggests a pitcher is struggling to strand runners.
What does LOB mean in a baseball box score?
In a baseball box score, LOB appears in the summary line alongside R (runs), H (hits), and E (errors). It shows the total number of baserunners each team left on base across the entire game.
What do all the letters on a baseball scoreboard mean?
The standard letters on a baseball scoreboard are: R (runs), H (hits), E (errors), LOB (left on base), BB (walks), SO or K (strikeouts), HR (home runs), DP (double plays), SB (stolen bases), MVR (mound visits remaining), and ABS (automated ball-strike challenges, new in 2026). LOB appears in the box score summary showing how many runners each team stranded.
What does MVR mean on a baseball scoreboard?
MVR stands for Mound Visits Remaining. Each team gets 5 mound visits per 9-inning game plus one extra per extra inning. The scoreboard shows how many visits each team has left. Once all visits are used, coaches and catchers cannot visit the mound — the pitcher must face the next batter.
What does ABS mean on a baseball scoreboard?
ABS stands for Automated Ball-Strike challenges, introduced in MLB in 2026. Each team gets 2 challenges per game to dispute a ball or strike call using an automated tracking system. A successful challenge is retained — the team keeps it. An unsuccessful challenge is lost. Teams receive one additional challenge per extra inning if both have been used.
What is LOB% for pitchers?
LOB% (Left on Base Percentage) measures the percentage of baserunners a pitcher strands over a season. The MLB average is around 72%. High-strikeout pitchers typically carry higher LOB% because they can pitch out of jams without relying on defense. A LOB% significantly above 75% may indicate positive regression is coming — the pitcher is likely benefiting from favorable sequencing.
What does LOB mean in softball?
LOB means exactly the same thing in softball as in baseball — runners who reached base but didn't score when the inning ended. It appears in softball box scores at all levels and LOB% for pitchers is tracked and interpreted the same way as in baseball.
LOB is one of those stats that looks simple on the scoreboard but tells a more complicated story underneath. For teams it measures how well they convert opportunities. For pitchers it is a window into clutch performance — and a strong predictor of ERA movement when it drifts too far from the league average of 72%.