Not sure where to start? These are the lessons and games we recommend most to students, parents and teachers on Basic-mathematics.com. Each lesson explains the topic in plain language, walks you through worked examples step by step, and ends with practice so you can check your understanding. Pick one below, or use the menu to find lessons on fractions, algebra, geometry, statistics and more.
To calculate earned run average (ERA) of a baseball player, just use the following formula:
Earned run average = (Number of earned runs × 9)/(number of innings pitched)
The formula above applies only to pitchers and it is used to determine how good a pitcher is.
The formula is used to find out how many runs a pitcher allows in a baseball game.
The lower this average, the better the pitcher is at not allowing runs in the game
Pitchers usually practice a lot to keep this number as low as possible.
When computing this average, we usually round answers to two decimal places
Example #1:
A baseball player had the following performance:
Allowed 4 runs
15 innings pitched
Earned run average = (Number of earned runs × 9)/(number of innings pitched)
Earned run average = (4 × 9)/(15)
Earned run average = (36)/(15)
Earned run average = 2.4
After rounding the answer to two decimal places, we get earned run average = 2.40
Example #2:
A baseball player had the following performance:
Allowed 7 runs
34 innings pitched
Earned run average = (Number of earned runs × 9)/(number of innings pitched)
Earned run average = (7 × 9)/(34)
Earned run average = (63)/(34)
Earned run average = 1.852941
After rounding the answer to two decimal places, we get earned run average = 1.85
Example #3:
A baseball player had the following performance:
Allowed 5 runs
32 innings pitched
Earned run average = (Number of earned runs × 9)/(number of innings pitched)
Earned run average = (5 × 9)/(32)
Earned run average = (45)/(32)
Earned run average = 1.40625
After rounding the answer to two decimal places, we get earned run average = 1.41
If you are a baseball coach, you may want to choose the player in example #3 because his average is lower.
However, no one so far was able to get an earned run average of 1.41. The ERA by the player in example #2 is close to what top players of all time were able to meet