What is LOB in Baseball?

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If you check box scores during or after a baseball game, you’ll see a section that says LOB in the batter’s stat line. You will also see a section for “Team LOB”. 

What does LOB in baseball mean? LOB stands for: Left On Base. Left On Base means the number of runners that were left on base at the end of the half inning. 

We also like to say the runners were stranded, like they were out on an island and not picked up or brought in. This means that a runner (or runners) was left on base after their team made the third out while batting. 

Left On Base is a great stat because it shows that opportunities to score runs were wasted, or “left”. This is particularly relevant when it’s a close game or low-scoring game because you can see in the box score how many chances a team or batter had to drive in a run but failed to do so. 

What is a good LOB in baseball?

For offense, leaving runners on base is never a good thing. The goal on offense in baseball is to score runs, as many as possible. 

That’s why RBI’s is such a good stat on offense because it shows that a player has the clutch ability to drive in runs, which matters most. Leaving runners on is basically failed opportunities to score runs. 

As a batter, you don’t want to leave runners on base. At the very least, you want to move them over to the next base. Striking out with runners on is the worst thing you can do. 

I could argue it’s worse than grounding into a double play because at the very least, if the batter puts the ball in play, it gives their offense a chance and makes the defense make a play. 

When looking at a batter’s box score or statistics, it’s simple – The more runners left on base, the worse it is. For example, if a batter has 4 at bats in a game and during those 4 at bats there were 5 total runners on base and not one of them scored; their LOB would be 5. 0% of the runners on base scored during the batters at bats. 

Not good. Even if the batter drove in just 1 of those 5 (20%), that 1 run could be all the difference in the final score of the game. 

As a batter, you have to “find a way”. If there’s a runner on third and less than 2 outs, hit a fly ball or ground ball to the right side. 

The run will score. Maybe there’s a runner on first and 2 outs, (which is much more difficult to drive in a run) but hitting an extra base hit will score that run. 

What about Pitchers LOB?

Leaving runners on base as a pitcher is a very good thing. Batters can get on base in all sorts of ways. From hits, walks, hit by pitch, and errors; it’s all part of the game. 

When a pitcher leaves runners stranded, it’s a form of baring down or being clutch enough to leave the runners stranded and thus, preventing the opposing team from scoring. 

As a pitcher, leaving runners on base is huge. Especially if you can induce a ground ball to get a double play or strike batters out with runners on. As far as statistics go for pitchers LOB, the below chart shows the percentages baseball uses, especially for relief pitchers, their ability to leave runners stranded.

  • Great = 78% and above of runners left on base that don’t score 
  • Above Average = 75% of runners left on base that don’t score
  • Average = 70% of runners left on base that don’t score
  • Below average = 70% and below runners left on base that don’t score

An example of the above is say a relief pitcher comes in and during their 2 innings of work, 4 runners reached base. But only 1 scored. 

That means 3 of the 4 runners on base during that pitchers outing didn’t score, so 75% That’s above average. Whereas in the same situation, if 2 of the 4 scored, that’s 50% and well below average. 

Relief pitchers of times come into games with runners already on base. Although those runners are technically their responsibility or their fault, it is their job to leave them stranded. 

That’s what makes a great middle inning relief pitcher. Being able to leave runners stranded, even if they are inherited runners.  

How is LOB calculated?

LOB% for a pitcher is calculated by dividing how many runners a pitcher leaves stranded on base at the end of an inning by the total number of base runners they allow. LOB% is also known as “Strand Rate” and only counts when a pitcher completes an inning. 

The formula is (H+BB+HBP-R) / (H+BB+HBP – 1.4 x HR). This isn’t as complicated as it looks and not necessary unless you’re diving deep into metrics. 

The best thing to look at for LOB is the box score. How many runners did a pitcher allow to reach base, and of those, how many scored?

For batters LOB, no calculation is needed. Go as simple as possible, how many runners were on base each time a batter was up to bat, and how many of those runners did they bring into score? If you bat 4 times in a game and no runners were ever on, you wouldn’t have a LOB calculation. 

If you bat 4 times and 4 runners were on base, and you brought in 1 to score, that’s 25%. In my opinion, that’s good. Any way of scoring runs is always a good thing. 

Typically, if a team has a lot of hits in a game but not a lot of runs, they left a lot of runners on base. But the reverse can also be true. A team can have a lot of hits and still leave a lot of runners on base.  

Example Box Scores

In the above example, this team had 12 runners left on base total of each batter by the end of the game. Yet they still scored 10 runs. Nobody is worried about their LOB since they scored 10 runs and won the game. 

The “Team LOB” is 6 because although the sum of each batter left on base was 12, the total at the end of each inning was 6. Remember, it’s the total left on base at the end of each inning. 

Here’s a better way to explain it. Say the leadoff batter gets on base. Then the next 3 batters get out. End of inning. Well each batter would have left 1 on base. But as a team, they left 1 total on base. 

Two things to note when looking at with the above box score. The 3 hitter only left 1 on base and had 3 RBI’s, meaning they did their job and drove in the majority of runners on base when they batted. While the 4 hitter left 4 runners on base and had 0 RBI, meaning none of the 4 runners on base during their at bats ever scored.

In the same game, the other team left a lot on base, and thus, only scored 3 runs. See below.

Although this team only had 5 hits, they also had 4 batters reach base via walk (BB). So 9 runners were on base but only 3 scored. 

That’s not terrible, but your offense must keep pace when the other team is taking advantage by scoring with runners on. 

What is the most LOB in a MLB game?

If you watch postseason baseball, it can be extremely dramatic and intense. I feel like when I watch postseason baseball, I see the LOB stat shown more often than regular season. That’s because the runs scored in postseason are so crucial. More important that ever. 

Especially because the amount of pitching changes in a playoff game, along with how close the games usually are. Each run is extremely important. I remember watching the Dodgers last postseason leave a ton of runners on base and then lose a game 2-1. 

This is a perfect example of why LOB is so important on offense, but also just as important for a pitcher and their defense. In that game, the Padres beat the Dodgers 2-1, but the Dodgers batters left 17 runners on base, as a Team they left 7. 

So, they had their chances to score more than 1 run. But on the flip side, the same is true for the Padres. Padres batters left a total of 21 on base, 6 as a team. In such a tight scoring ball game, each run is so crucial and leaving runners stranded is amplified. 

The most runners as a team LOB ever in a 9-inning baseball game is 20, set by the New York Yankees in a 13-7 loss on 9/21/1956. The most LOB in any length baseball game was 27 by the Atlanta Braves on 5/4/1973. 

What’s very interesting to me is looking at Team LOB in 2022. The Padres and Dodgers on average left the most runners on base per game, at 7.20 and 7.17 respectively. On average, those two teams left 7 runners on base as a team in 2022 per game. 

Even though that seems like a bad thing, both teams made playoffs and were in the top 5 of runs scored per game. This just means that they had a lot of runners reach base on average per game. 

On the other side, the Oakland Athletics left less than 6 runners on per game as a team. They were the worst offense in baseball last season, but still managed to make the most of their opportunities and brought in runs to score more often than other teams. 

LOB% for Pitchers

One of the leading metrics teams look at nowadays is LOB% for pitchers. This is a relief pitchers main job, leave runners on base! The league average in 2018 was 73.1%. Meaning 73% of runners on base did not score on relief pitchers throughout all of baseball. 

The top 15 relief pitchers for LOB% in 2018 all had 80% LOB% or above. The chart below shows the percentage of runners left on base by each of the top 15 relief pitchers for LOB% along with the K% (strikeout percentage) and ERA. It’s no surprise that most of these pitchers have a high K% and low ERA. 

How nice is that for the managers of Jeffress and Iglesias? Knowing that +90% of the runners on base when they come into pitch will be left on base and not score. And that 30% of them will strikeouts. Those are marks of an elite relief pitcher. 

In the same year, we look at starting pitchers and their ability to leave runners on base that they allowed to reach base. The league average was 72.6% of runners who reach based by a starting pitcher, were left on base. Based on what we said earlier, 75% and up is above average. 

We see that Blake Snell had a whopping 88% of the runners he allowed to reach base not end up scoring. And with that, his ERA was a miniscule 1.89 along with his K% at 31.6%. Elite status. Mike Fiers had a much lower K% and ERA but high contact %. 

For having nearly 86% LOB%, it meant he found a way to get outs, probably via ground balls and double plays to allow his defense to help prevent runs score. 

Wrap up

LOB means, Left on Base. For batters or offense, the more LOB, the worse. This means that your offense and your hitters left runners on base when you needed to find a way to bring them in to score. 

If your team reached base whether it’s from hits, walks, hit by pitch, or errors; but you didn’t score a lot of runs, the first place to look is the LOB line in the box score. Those are missed opportunities for runs. 

LOB% for pitchers though, the higher the %, the better. This means as a pitcher, you did not allow baserunners to score. 

It could mean a result of strikeouts or finding ways to have balls batted in play result in outs. The best thing you can do as a relief pitcher is not allow baserunners to score, especially inherited runners. 

Next time you watch any baseball game, key in on the number of baserunners in contrast to how many actually end up scoring. 

You’ll quickly notice if the offense is coming through for their team and bringing in runners, or if the pitcher and defense is baring down and preventing those baserunners from touching home plate.