What Is The ERA In Baseball Mean?

When I first got serious into baseball, I had a few stumbling blocks. There was a lot of information to learn many new concepts to get a grasp of. One of the more challenging things to comprehend is all of the statistics and what importance they all have. If you have the same struggles as me, I hope that I can help.

I have put together a bit of an explanation of some of the most difficult aspects of statistics. So if you are wondering what ERA means, you are in luck because I am here to give you a full rundown of this measurement in baseball statistics.

What is ERA?

ERA stands for Earned Run Average. Simply put, this is the number of runs that a particular pitcher allows for every nine innings he or she pitches. The earned run average is one of the most important statistics to look at when you are analyzing the statistics of a baseball pitcher. This number gives you an estimate on how many times during an inning the opposing team has earned a run against this particular pitcher.

How is it calculated?

To calculate this number, you first need to count up all of the runs earned against the particular pitcher that you are trying to figure for. Once you have their total runs earned against them, take that number and divide it by the total number of innings pitched. Take the result of that calculation and multiply it by nine.


This calculation is best for the standard pitchers. The calculation can be skewed for relief pitchers or unusual circumstances. On average this is a useful number that can be reliable, but there are those rare circumstances that make the math confusing or come up with

See also  How to Determine the Size of Softball Bat to Use

Why is this number important?

The earned run average is the fairest way to judge a pitcher’s performance. The reason this is is because it helps weed out statistical anomalies that may be present because of the rest of the team’s defenses. This number also allows you to see the performance of the pitcher against the performance of other pitchers as well. It gives a fair metric that can be used to judge the overall performance of the players.

Context of the ERA

The meaning of the earned run average has changed over time. This is because the game has evolved over time. Due to these general changes to the game, it is hard to compare modern pitchers earned runs average with that of players throughout history. The comparison may just not be what it implies. There are too many changes in the game for these comparisons to be fair and representative of reality.

For example, very early on the pitcher’s mound was much closer to the batter. This resulted in a skew of the earned run average being quite a bit lower than you will find today. This is why you will find early era pitchers with earned run average numbers close to the low 2.00s. Today’s pitchers are far more likely to be around 4.50.

See also  How to Have Perfect Slow Pitch Softball Swing


This number can also fluctuate depending on a player’s rotation. A relief pitcher, for instance, may have a much higher earned run average when compared to other pitchers. If they simply let a few runs through they can struggle to bring down the number through the rest of the year.

Is ERA the best statistic for pitchers?

The earned run average is a great number to look at when judging the efficiency of a pitcher. But is it the best statistic to look at? There are plenty of other numbers out there, and maybe one of them is more representative.

Well, you can look at the win-loss record of a pitcher, but I would not consider this representative to the pitcher alone. A pitcher cannot adequately control the entire defense, nor be held responsible for the offense of the rest of his team, and it doesn’t seem reasonable to hold them responsible for that.

Some others like to look at strikeouts as a metric to judge the pitcher. People like to look at the percent of batters that a pitcher as struck out over time. This number will tell you how often a pitcher can miss the bat and keep the ball from seeing play. This can be a good measure, but I think it is not always the best way to look at the numbers.


Another school believes that the walks and hits per inning, or WHIP for short, is the best metric. This is a simple number to come up with. It is essentially the number of his and walks added together divided by the number of innings pitched. Some like the simplicity and straightforward nature of this number, and I would agree that the WHIP is a great measurement and is a great representation of a pitcher’s performance. It may be one of the only measurements to rival the tried and true earned runs average, but I am one that like the traditional measurements so for me the Earned runs average wins out.

See also  How To Measure Handicap In Baseball Betting

The way to compare pitchers

The earned run average is a number that people use to judge a pitcher’s performance. It takes the number of runs earned against a pitcher, divided by the number of innings they have played and multiplied by nine. This number is used to compare to other pitchers and so make predictions on how the pitcher will do in following games.

In context, the number has been skewed through history by a number of factors so that looking at the earned run average of players through history may not be comparable to the players in the modern version of the game.

There are other numbers that some people use to compare pitcher metrics. Some of them are better than others. In particular, the use of WHIP (walks and hits per inning) is a useful metric. It almost rivals the use of earned run average in usefulness, though I prefer the ERA.

If you have questions or comments, please feel free to leave them below.

About The Author