Baseball Stats Explained: What Is OPS, WHIP, ERA, OBP, SLG, And More? ?

Even the most cursory glance at baseball and you can see that it’s numbers heaven. Statistics are part of all sports, but with the advent of sabermetrics, baseball has elevated them to an edifying, almost cult status.

There was a time when statistics were considered supplemental information, perhaps to help you understand trends, but the a real knowledge of the game, intuition if you will, was the important element.

Then the Oakland A’s, in an effort to compete in a sport where they had no money to bet, notoriously paid attention to the writings of Bill James and changed baseball forever.

The numbers were gone objective looking at what had happenedlike ERA or batting average, but they have become subjective in what they tried to predict what was likely to happen in the futureand so statistics like OPS+ and SLG were born.

There are an impressive number of stat categories, with everything in baseball is counted and quantifiedbut here is a basic introduction for the casual viewer.

To hit

Offensive stats are dominated by what happens on the plate. Of course, there are plenty of others dealing with all aspects of basic running, but the main takeaways relate to batting.

To bats (AB)

This one looks simple enough, but like everything in baseball, there’s a sting in the tail. In bats, represented by AB in a box score, are exactly what it says on the tin: how many times a player has come to home plate to beat. They could have gotten a hit, a strikeout, or been on base via an error or a fielder’s pick play. Where you can be confused as a novice is understanding that a walk, whether four-ball or being hit by the pitch, or a sacrificial play does not count as an at bat. So a player can par 0 for 0 with a walk.

Plate Appearances (PA)

It’s the same as At Bats, but includes walks and sacrifice games, taking a more literal interpretation of the name. The only time a plate appearance is not recorded is if the catcher interferes with the batter. The batter will be awarded first base and neither an at-bat nor an appearance at home will be recorded.

Run (R) and Runs Batted In (RBI)

A run is scored when a batter bypasses all bases and safely hits home plate, regardless of whether it was by their own blows or if they were pushed by someone else. In the latter case, a run batted in, or RBI, will be awarded to the batter who actually hit the ball to drive into the run.

Strokes (H)

A hit is when the batter puts the ball in play and reaches the base safely, but there is a caveat here. A batter can reach base by a defensive error, either fielding or pitching, or by fielder’s pick, i.e. when a fielder kicks out a baserunner at a different base instead of the batter at first. In either of these cases, it does not count like a blow.

There are other breakdowns of the hit stat based on how far the batter hits, whether it’s a single, double, triple, or home run. These would be represented by 2B, 3B and HR rather than just H, indicating a single.

Base on balls (BB)

It’s another way of saying walk. Used only when a batter sees four balls while at bat, whether it is an intentional walk or not. If the batter is hit by the pitch (HBP), it is not counted as a base on ball but falls into that separate category.

Barred (K)

Whether a batter misses three pitches, it is recorded as a strikeout and written in the logbook as the capital letter K. This indicates that the batter swung the bat and missed. If he is called without swinging on the third shotthe capital letter ꓘ is written upside down.

Batting stats

Understanding how a batter performs over time is key to key batting statistics. The holy grail, for over a century, has been batting average. In recent years, this has given way to on-base percentage and slugging, but let’s take a look at what it all means.

Batting average (AVG or BA)

As with any average exercise, you simply take the number of hits a player has so far in the season and divide that by the number of hits at bat. The number is expressed in thousandths, so someone who hits 3 out of 10 at bats would have a batting average of .300.

On Base Percentage (OBP)

With hitting statistics prohibiting some of the other ways a batter can reach base, modern teams tend to rely on a batter’s on-base percentage as the gold standard, since it includes walks and kicks on the pitch. Considered a fuller picture of a batter’s ability, it always discounts errors and fielder picking, as they have nothing to do with the batter.

Strike (SLG)

Slugging is a new concept (anything in baseball under 50 is considered “new”) and takes the total number of bases a batter has hit (remember that doubles, triples and home runs were counted separately) and divide this number by at-bats. The purpose of this stat is to show the power of a hitter and to rate a homerun hitter versus a guy who is hitting singles in the outfield.

This is a somewhat controversial category because using this statistic, Hall of Fame players like Rod Carew or Rickey Henderson who relied on bunts, singles and rides before doing their heavy lifting on the base paths, would have been considered a disability in a batting formation.

On base plus slugging (OPS)

This is often taken as an overview of a batter’s production, as it examines how often does a batter get a base and how often does he get extra bases.

Launch statistics

On the other side of the equation, the defensive stats are pretty much dominated by throwing. Here is an overview of the most important of them.

Innings pitched (IP)

The number of innings a pitcher pitches in a game is represented by an integer and a decimal. Rather than being a split of ten, however, the decimal is a split of three, with three outs making a full inning.

Hits (H), Runs (R) and Runs Earned (ER)

As on the offensive side, hits and runs are charged to the pitcher who relinquishes one of them. An earned run is a statistic exclusive to pitchers and indicates the number of runs scored as a direct result of work done by the batter, as opposed to a walk or error.

Base on balls (BB), strikes (K) and home runs (HR)

Exactly with regards to batters, the pitcher is in charge of anyone he yields to a batter.

Number of pitches (PC) and strikes (ST)

This is simply an accounting exercise, but in baseball we keep track of how many pitches a given pitcher has thrown on an outing and the total number of pitches thrown for strikes. This is often used to give a picture of a pitcher’s durability, or vice versa, how much may be left in the tank.

An over-reliance on these stats, especially pitch counts, has become a much-criticized feature of the game over the past decade.

Wins (W) and losses (L)

Obviously, if the pitcher’s team wins or loses the game, that should be the corresponding stat for him, right? Not so fast. A pitcher only receives one win if they were on the mound when their team took the leadand they receive the loss if they were on the mound when their team gave up the lead.

If a pitcher enters a game with a lead of three runs or less, and there is a situation where the opposing team could tie the game, and he then stops it, he receives a stoppage (S) .

Earned race average (ERA)

The standard by which pitchers have been measured for over a century, ERA is calculated by the number of earned runs they allowed divided by the number of innings pitched, then multiplied by nine, meaning the lower the number, the better the pitcher’s performance.

With the advent of sabermetrics, several other calculations have emerged that are believed to more fully represent a pitcher’s value to a game’s outcome.

Field Independent Launch (FIP)

Field-independent pitch is one such calculation and it attempts to remove field factorsfor example if a ball was hit for a ground to second base or a short pop fly to right field, from pitcher stats, instead focusing entirely on balls and hits.

Purists complain it’s a general misunderstanding of the game of baseball as a team sport and that a pitcher who can force a lot of takedowns on the ground is worth his weight in gold.

Walks plus hits per inning pitched (WHIP)

Another attempt to give a more balanced view of a pitcher’s performance, and arguably more accurate than FIP, is walks plus hits per inning pitched, which calculates the total number of base runners allowed by a pitcher per inning. This is a more robust view of a pitcher’s effectiveness against batters, and ultimately that’s what you want to know.

Admittedly, this isn’t a perfect category of stats, but again, none of them are, showing that at the end of the day, numbers can only tell you a lot about what will happen when the ball will be thrown over the plate.

Neal T. Doss