What is ERA in Baseball?

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In the Baseball game, ERA is known as Earned Run Average. With time, advancements in the evaluation criteria of accessing the performance of a baseball player came into the Baseball game. The criteria for the evaluation has been evolved. Let’s find out the answer to this Question: ‘What is ERA in baseball’ in detail.

Pitchers are considered to be one of the most critical assets of a Baseball team, so Earned Run Average (ERA) was introduced for scrutiny purposes. Of the pitchers. An ERA is the most commonly used and accepted statistical tool for evaluating pitchers. The main purpose of pitching is to prevent the opponent from scoring, and Earned Value Average (ERA) tells exactly about this.


What is ERA in Baseball?

Earned Run Average (ERA) is a statistic in the Baseball game used for the evaluation of a pitcher’s average of earned runs allowed per nine innings pitched (as it is the traditional length of a Baseball game). Dividing the total earned runs allowed by the pitcher by the number of innings pitched and multiplying the result by 9 gives the value of earned run average (ERA).

Earned run average represents the number of earned runs a pitcher allows per nine innings — with earned runs being any runs that scored without the aid of an error or a passed ball. ERA is the most commonly accepted statistical tool for evaluating pitchers.



Who was the man behind the creation of ERA?

Credit for creating the ERA goes to the ‘Father of Baseball’ Henry Chadwick‘. He was a sportswriter and also a Statistician. He not only created ERA but also played a vital role in other parts of the game like batting average, abbreviating the strikeout with the K letter, and the box score.

Chadwick created ERA in the mid-to-late 19th century but the exact date is still unknown. This stat reaches its popularity when relief pitchers made a prominent entry in the game. The introduction of relief pitchers made wins or loses records even less dependable. Starting pitcher may end up with a loss even if he pitched a great game because his relief pitcher could not do well.

The need for the Earned Run Average (ERA) was felt because earlier pitchers’ ability was assessed based on wins or losses. Chadwick insisted that only wins and losses are not the true indicators of a pitcher’s effectiveness in the game, he believed something quite specific is the need of the hour.

How does ERA work?

Earned run in the Baseball game is a run that is scored due to the ability of the pitcher without a fielding error or any other factor. While an unearned run is any run that occurs due to an error or a passed ball.

Earned runs are the most common runs and account for 92% of the total runs scored which is 23,467 during the Major League Baseball (MLB) season in 2019. These runs scored as a combination of hit batters, walks, and well-time outs. While unearned runs are quite rare and account only for 1783 runs during the MLB season in 2019.

How does ERA work

The pitcher’s job description in Baseball is quite simple, preventing the opponent team from earning the scores is the responsibility of a pitcher. As Earned Run Average (ERA) of a pitcher shows the average number of earned runs allowed in a nine innings game, it is quite an amazing evaluation measure to determine how well a pitcher has achieved the goal.

So, an ERA value is giving the statistic that how well or bad a pitcher is performing in a season. It gives a ballpark figure about the pitcher’s performance.

How is ERA calculated?

Earned Run Average (ERA) is calculated with a formula. As per the definition of the ERA, the formula for calculating ERA is quite simple:

ERA = (Total number of the allowed earned runs / Total number of the pitched innings) * 9

The value of this formula gives the average number of the earned score allowed per inning. ERAs are two decimal places. Depending on the review purpose, it provides the averages for a season or a career of a pitcher.

How to calculate ERA

Example of ERA calculation:

Let’s take an example and put values in the above formula to calculate ERA.

For example, a pitcher has pitched 120 innings. In the total of 120 innings, he allowed only 60 runs. From 60 runs, 50 were earned and 10 were unearned. Earned runs will be considered for the ERA calculation.

We have the total allowed earned runs and total pitched innings. So, the ERA calculation will be like that for this case:

ERA = (Total number of the allowed earned runs / Total number of the pitched innings) * 9

ERA = (120 / 50) * 9

ERA = 3.75

So, the pitcher’s ERA is 3.75 for the season.


What is a Good ERA in Baseball?

After knowing the ERA of a pitcher, it is important to know what is ERA in Baseball in terms of good or bad value. There is no hard and fast rule about the exact value of a good ERA.

Several factors are responsible for the fluctuation in the ERA value including but not limited to the League’s quality of hitting or pitching, dimensions of the ballpark, elevation, and other stuff.

As ERA is the ability of a pitcher to prevent the opponent from scoring earned runs, a lower ERA shows that a pitcher allowed the hitters to earn less score. A higher ERA means opponent hitters were able to score more runs, so a lower ERA represents the good performance of a pitcher.


What is ERA in baseball

Image: What is ERA in baseball




Good ERA value Range:

In today’s era of Baseball, the ERA value of pitchers less than 4 is considered a good ERA. Below 3, ERA value is considered great. Pitchers having an ERA value below 2 is quite rare. Only exceptional pitchers have less than 2 ERA values.

Bad ERA Value Range:

The performance of a pitcher is pretty much bad if the value of the ERA is 5 or anything above 5. Pitchers with this value range usually play in the minor leagues or pitch in blowout games.


Statistics about ERA in Baseball History

There are quite interesting statistics about pitchers in Baseball history having pretty good and quite bad ERA values.

What is ERA in Baseball - Statistic

Pitchers Having Great ERA in their career:

Ed Walsh:

Ed Walsh was a super star in the Baseball game and a role model for many Baseball pitchers. Ed Walsh played for seven seasons between 1906 and 1914 and earned the lowest ERA of 1.79. He holds the record for the lowest ever career-best ERA.


Eddie Joss:

Eddie Joss played from 1902 to 1910. Joss’ ERA of 1.89 is the second lowest ever ERA after Ed Walsh. In Baseball History, he also had the honor of pitching the fourth perfect game.

Jack Pfiester:

Jack played for the Chicago Cubs and Pittsburgh Pirates in Major League Baseball (MLB). With his help, Curbs won two World Series Championships. Jack had an amazing 2.024 value ERA during his career.

Bob Gibson:

Bob Gibson was also a big giant in the Baseball game. His career was of 17 long years. He earned a 2.91 ERA and played for St. Louis Cardinals.

Tommy Bond:

Tommy was a star pitcher in Major League Baseball (MLB) for ten seasons. During his whole career, Bond had played for six teams. He stands out in the list of best pitchers with a career ERA value of 2.138.

Smoky Joe Wood;

Smooky played from 1908 to 1915 from the Boston Red Sox. Smooky had a quite distinguishing record to his name, he was one of only 13 these pitchers who had won 30 or more games in a single season. Smooky Joe Wood had the career ERA having 2.033 value.

Babe Ruth:

Red Sox’s Babe Ruth was a true legend of the Baseball game. This left-hand pitcher performed exceptionally well and got a 2.28 career ERA.

Pedro Martinez:

Red sox’s other modern-era legend is Pedro Martinez. He has earned a career ERA of 2.93. Pedro’s best ERA is 1.74 in the 2000 season.

Dutch Leonard:

Dutch Leonard earned the ERA of 0.96 in the American League played in 1914. This extraordinary left-handed pitcher had an ERA of below 1 in a single season.

Tim Keefe:

Tim Keefe has a unique record to his name. He achieved a rare milestone. He has the lowest ever one-season ERA of 0.86. He was playing for the National League Troy Trojans in 1880.

Dazzy Vance:

Dazzy Vance was a symbol of FastBall in Baseball. He received a 2.16 ERA during his best performing season happened in 1924. Dazzy has the honor to lead the National League for seven consecutive seasons in strikeouts.


Earned Run Average 2016 -2017








Worst ERA value (Minimum 60 games)

This is quite an unfortunate statistic for the pitchers.

Some players (minimum 60 games) have lowest value of ERA including but not limited to:

Jesse Orosco       7.75

Alan Embree       7.62

Javier Lopez        7.52

Brad Lidge           7.48

Mike Munoz       7.42

Bobby Ayala       7.29

Norm Charlton  7.27

Shawn Chacon  7.11

Jim Poole           7.11

Andrew Sisco    7.10

Can a pitcher have zero ERA value?

Earned runs account for almost 90% of the total runs in Baseball. While unearned runs are quite rare. Earned runs play an important in evaluating ERA.

A pitcher can have a zero ERA value technically but it does not show his skill. Undefined or the infinite ERA is also the other name for the zero ERA.

It is quite easy to understand that at the start of the season, ERA can be zero, because there are statistics yet to come for the complete game. Imagine a scenario in which the pitcher allows one or more than one earned run without retiring the batter, obviously there will be zero ERA because it did not involve any outs. But as far as the whole season is concerned, a pitcher will not have zero value of ERA.

What is ERA in baseball


What is ERA in Baseball’ answer seems quite straightforward but it needs some things to explain and this is what we discussed in this article.

ERA replaces the simple wins and losses older method of evaluating a pitcher and provides a better assessment metric for the effectiveness of a pitcher in the Baseball game. An ERA is the best tool to evaluate a pitcher’s ability and with this statistic, one can compare the different pitcher’s ERA values. ERA value adds value to the Baseball game.

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