Have you ever noticed the people at a baseball game who look like they’re taking notes? That’s the lost art of scorekeeping and it’s key in keeping track of every single play on the baseball field and recorded as a stat.

Stats are everything in baseball and rooted in the deep traditions of the game. So for nearly every play imaginable, a stat is sure to exist.

Events like, “Pinch runner who has hit more than two home runs during a game wearing the No. 6” seems like information overload, but many stats like this are crucial to the game.

With baseball season underway, let’s go through some of the most important baseball stats…


Batting Average

The total number of hits a player has divided by the total number of at bats. It is expressed as a three place decimal but recited as a whole number. In other words, a player’s batting average will be written as .278 but an announcer will say the player is “hitting two-seventy-eight.”


Key Batting Averages

  • 400: It is an incredible achievement to hit .400 over the course of a whole season. In fact, the last player to do it was Ted Williams all the way back in 1941.
  • 300: This is the defining line between having a good season and a great one. Hitting .300 is what all players strive to do at the beginning of the season.
  • 200: This is known as the “Mendoza Line” (named for utility infielder Mario Mendoza). Hitting below .200 is unacceptable at the major league level.


Batting Average with runners in scoring position

Base-runners on second or third base are in “scoring position” because they can try to score on a single to the outfield. A player’s batting average with runners in scoring position is a way to measure whether that player gets meaningful or “clutch” hits.


Earned Run Average

Frequently referred to as “ERA.” The total number of earned runs allowed, divided by innings pitched, times 9. An ERA under 4.00 is very good. An ERA under 3.00 is excellent.


Innings Pitched

This pitcher’s stat is counted by number of outs, and is expressed in thirds. If a pitcher completes five innings and then gets two outs in the sixth inning, he is credited with 5 2/3 innings pitched. Although inaccurate, if expressed as a decimal, it would be written 5.2.


Left On Base

Sometimes written as LOB, this measures how many runners reached base and did not score. It is typically expressed as a team stat for a game.


On-Base Percentage

This factors in how often a player can draw a walk. It is the total number of hits plus walks, divided by total Plate Appearances (At-Bats plus Walks).



On-Base Percentage PLUS Slugging Percentage. This is the stat that many experts say is the best indicator of who the best player is at any given time.



Runs batted in. Anytime a player gets a hit and a base runner scores on that hit, the player is credited with a run batted in.

If a player hits a home run, he is credited with a run batted in for himself scoring as well. Although the word “run” is the plural in this stat, the plural of RBI is RBIs, not RsBI. This stat is also sometimes called “ribbies”.


Runs Created

This is the total number of runs scored by a player, plus the total number of RBIs, minus the number home runs hit.  The reason you subtract the home runs is that on each home run a player is credited with both a run scored and an RBI, even though it produces only one run.


Runs and Earned Runs

When a pitcher allows a man to reach base, he is charged with a run if that runner scores, even if he is taken out of the game and a new pitcher is on the mound when the base runner scores (for the relief pitcher who came in, he is charged with an “inherited run” or “inherited runner scored” in that situation).

“Earned Runs” is the number of runs a pitcher allows other than those attributable to errors. If a man reaches base on an error and scores, the pitcher is charged with a run, but not an earned run. In addition, if an error occurs in an inning, any runs that score once there are two outs in the inning are unearned runs (because in that situation the inning would have been over had the error not occurred).



While there are complicated rules for when to award a save, the most common is a pitcher who successfully finishes a game protecting a lead of three runs or less.


Slugging Percentage

A players Total Bases divided by At-Bats. Expressed the same way as a batting average (e.g. .645)


Total Bases

This adds up the players hits, awarding 1 for a single, 2 for a double, 3 for a triple, and 4 for a home run. This is a way to measure hitting and factor in power.



Walks Plus Hits Per Innings Pitched: Total number of walks, plus total number of hits, divided by innings pitched.  This is thought to be one of the best measures of effective pitching. A WHIP of under 1.000 is outstanding.


Featured image via Scanvive


Editor’s Note: This was originally published in 2015 and spruced up in 2022