What Is LOB in Baseball & LOB Formula Explained

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Baseball, often described as America’s pastime, is a sport rich in statistics and strategic nuances, each adding depth and excitement to the game. One such term that frequently appears in baseball analytics is “LOB,” an acronym that stands for “Left On Base.” This concept plays a crucial role in understanding the flow of the game, offering insights into a team’s performance and scoring opportunities. In this section, we’ll explore the significance of LOB in baseball, shedding light on how this statistic influences game outcomes and team strategies.

What Is LOB in Baseball?

LOB stands for “Left On Base” in baseball terminology. It refers to the number of base runners a team has left on base at the end of an inning when their turn at bat concludes. This statistic is significant because it reflects a team’s potential to score runs that were not realized. A high LOB count in a game suggests that a team had many opportunities to score but struggled to bring runners home, which could be due to strong defensive plays by the opposition or a lack of timely hitting. Tracking LOB can provide insights into a team’s offensive efficiency and clutch hitting performance.

Understanding LOB with Example

Let’s break down the concept of “Left On Base” (LOB) in baseball with an example:

Imagine a baseball game between the New York Yankees and the Boston Red Sox. In the bottom of the first inning, the Red Sox load the bases with no outs but fail to score any runs. This means they had three runners on base (loaded bases) but couldn’t bring any of them home to score.

Now, in this scenario:

  • The Red Sox would have three LOB for that inning because there were three runners left on base when the inning ended.
  • LOB indicates missed scoring opportunities. In this case, despite having runners in scoring position (on base), the team failed to capitalize and score runs.

LOB Formula in Baseball

The LOB% (Left On Base Percentage) is a formula used in baseball to measure the percentage of base runners a pitcher leaves on base over the course of a game or season. Here is the formula:


LOB% = (H + BB + HBP – R) / (H + BB + HBP – (1.4 * HR))


In this equation:

  • `H` stands for hits allowed by the pitcher.
  • `BB` represents the number of bases on balls (walks).
  • `HBP` is the number of hitters hit by a pitch.
  • `R` denotes the total runs allowed.
  • `HR` is the number of home runs allowed.

This calculation provides a percentage that represents how effective a pitcher is at avoiding runs after allowing batters to reach base. A typical LOB% falls between 70-72%. This means that, on average, pitchers leave 70-72% of base runners stranded on base without allowing them to score. If a pitcher has a LOB% significantly lower than the league average, it suggests they are less effective at stranding runners, typically resulting in a higher ERA (Earned Run Average). However, pitchers with abnormally low LOB% are likely to see improvement over time as their performance adjusts towards the average. Conversely, pitchers with very high LOB% might experience a regression, leading to more runners scoring in the future. This metric is invaluable for predicting future performance adjustments for pitchers.

Is High LOB is Good in Baseball?

Having a high LOB% is generally considered good in baseball because it means the pitcher is effective at stranding runners and preventing them from scoring. This allows the team to keep the game close and gives them a better chance of winning. However, there are situations where a very high LOB% can be seen as a negative. For example, if a pitcher has an abnormally high LOB% because they are consistently getting themselves into trouble by allowing too many runners on base, it could suggest underlying issues with their performance that may impact them negatively in the future. Therefore, while a high LOB% is generally seen as a positive for pitchers, it is important to consider other factors such as overall pitching ability and tendencies when evaluating this metric.

Does a LOB Count as a Base?

No, a LOB (Left on Base) does not count as a base in baseball. It is simply a statistic that tracks the number of base runners who were left stranded without scoring during a pitcher’s outing. A LOB only counts as an out for the opposing team and does not affect the offensive team’s statistics. However, a high LOB% can be indicative of a pitcher’s ability to strand runners, which can have a positive impact on their overall performance and the team’s success. So while it does not technically count as a base, a high LOB% is still an important metric to consider in evaluating a pitcher’s effectiveness.

What is a Good LOB for Pitchers?

A good LOB% for pitchers is typically around 70-75%. This means that the pitcher is effectively stranding approximately 70-75% of the base runners they allow on base. A higher LOB% is generally seen as better, as it suggests the pitcher has a strong ability to prevent runs from being scored. However, a very high LOB% (over 80%) can also be cause for concern as it may indicate a reliance on luck rather than skill. Therefore, it is important to consider other factors in conjunction with LOB% when evaluating a pitcher’s performance.

Does Double Play Count as LOB?

No, a double play does not count as a LOB. A double play occurs when the defensive team records two outs on one play, typically by forcing a runner out at second base and then quickly throwing to first base for another out. In this scenario, the base runners are not left stranded and therefore do not contribute to the LOB statistic for the pitcher.


Understanding the nuances of the Left On Base percentage (LOB%) is crucial for comprehensively evaluating a pitcher’s performance in baseball. A good LOB% showcases a pitcher’s knack for stranding runners on base, significantly contributing to preventing runs and cementing games in their team’s favor. While a high LOB% is generally favorable, it’s important to balance this metric with other performance indicators to gauge a pitcher’s effectiveness accurately. Remember, factors like double plays impact the game dynamically but don’t directly influence the LOB statistic. Baseball, with its intricate statistics like LOB%, highlights the depth and complexity of the sport, making it as much a game of numbers as it is of skill and strategy.

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James Arnold
I'm James, and I live in Stanislaus County, California. I'm playing Baseball for many years, and I love this sport so much that I also encourage my kids (Danny and Sara) to play Baseball & Softball.