Baseball is arguably the most statistic-driven sport. Indeed, virtually everything that happens during a game can be recorded on the score sheet and categorized numerically. In recent years, fans and analysts have utilized technological advances to create new, often more complex ways to evaluate player performance.

The 21st century has ushered in what could legitimately be deemed a statistical revolution. And in order for us as players and fans to keep up with the trends of the sport, we must acquaint ourselves with some of these brand new stats.

What follows is an overview of some of baseball’s most prevalent offensive statistics. To keep this list more concise, it will not go over “counting” stats such as runs, hits, doubles, home runs, walks, strikeouts, stolen bases, and sacrifices. These statistics are certainly still significant, but neither their origins nor their means of evaluating performance require any further explanation.

## Standard Batting Stats

If you watch baseball regularly, chances are you’ve come across the following five statistics. With the exception of OPS (which has been around less than 30 years), they’re all ingrained in the baseball vernacular, having been used since the game’s early days.

### Batting Average

Calculated using the simple formula of hits divided by at-bats, batting average has always been the standard for measuring offensive success. In the big leagues, the player with the highest annual average is awarded with the “batting title.”

The drawbacks of batting average are that it doesn’t credit a hitter for reaching base via a walk, nor does it account for run production or extra-base hits. Furthermore, many statisticians believe that constructing an average based solely on hits is not sufficient enough to accurately gauge batting prowess.

### On-Base Percentage (OBP)

More inclusive than batting average, OBP measures the frequency at which a player reaches base, using the following formula:

**OBP = (hits + bases on balls + hit by pitch) ÷ (at bats + bases on balls + hit by hitch + sacrifice flies)**

Many people place more value in OBP than batting average. This is because, ultimately, a hitter’s individual goal is to reach base. In this way, on-base percentage more fully reflects a batter’s success rate.

### Runs Batted In (RBI)

If you get a base hit, force out, fly out, walk, or hit by pitch that directly results in a run being scored, you are credited with a run batted in. For years, RBI was one of the most important offensive stats, which is understandable, since the ultimate goal in baseball is to score runs. Recently, with the advent of Sabermetrics, RBI’s value as a statistic has taken a hit.

Statisticians argue that RBI is far too contingent upon factors that a hitter cannot control, most importantly, whether runners are on base when a hitter bats. While batters that accumulate a lot of RBI are undoubtedly successful run-producers, it’s also true that the players with the most RBI are typically the players with the most RBI opportunities.

### Slugging Percentage

Slugging percentage basically gauges a player’s power by measuring all of the bases accumulated via base hits. In order to have a high slugging percentage, a batter must not only be a successful hitter, he must also hit frequently for extra bases. The formula divides total bases by at-bats:

**Slugging percentage = [singles + (doubles × 2) + (triples × 3) + (home runs × 4)] ÷ at bats**

In many instances, the players who hit the most home runs will also be among the leaders in slugging percentage. It doesn’t necessarily measure how good of a hitter you are, as much as it measures how dangerous of a hitter you are.

### On-Base Plus Slugging (OPS)

This stat was first conceived in the 1980s, and is considered by some to be the first Sabermetric statistic. OPS measures exactly what its name suggests: On-base percentage plus slugging percentage. Essentially, OPS takes two useful stats and puts them into one category. It measures a player’s ability to get on base, as well as his ability to hit for power. Many people believe that OPS is the most accurate and comprehensive indicator of the best hitters.

## Sabermetric Batting Stats

The term “Sabermetrics” is derived from the acronym SABR (the Society of American Baseball Research). The concept was pioneered most famously by stat-innovator Bill James, who defined Sabermetrics as, “the search for objective knowledge about baseball.” In this spirit, the following statistics possess varying degrees of complexity, but all are designed to precisely reflect a player’s measurable value to his team. There are dozens of Sabermetric stats in existence, but the five on this brief list are among the most accessible and comprehensive.

### Runs Created

James developed this stat in order to quantify the numbers of runs a hitter directly creates for his team over the course of a season. His rational was that a hitter’s job isn’t to get base hits and draw walks, but to put runs on the scoreboard. And yet, no single stat had previously been able to measure a player’s individual impact on team run-production. James originally used a simple but flawed formula that has since been refined (and made much more complex):

**Runs created = [(hits + bases on balls + hit by pitch – caught stealing – grounded in double play) × (total bases + .26[bases on balls – intentional bases on balls + hit by pitch] + .52[sacrifice hits + sacrifice flies + stolen bases])] ÷ (at bats + bases on balls + hit by pitch + sacrifice hits + sacrifice flies)**

### Isolated Power

Isolated Power is a measure of a hitter’s raw power, essentially reflecting extra bases per at-bat. Those players who accumulate a lot of total bases also tend to post high Isolated Power numbers. It can be found using either of two relatively simple formulas:

**Isolated power = (slugging percentage – batting average)****Isolated power = [doubles + (triples × 2) + (home runs × 3)] ÷ at bats**

### Secondary Average

This stat was created as a way to look at a player’s extra bases gained, independent of and complementary to, standard batting average. By accounting for extra base hits, walks, and stolen bases, secondary average is a more complete reflection of total production. It has a much greater variance than batting average; the leading MLB hitters are typically up near .500. It is calculated with the following formula:

**Secondary average = (total bases – hits + bases on balls + stolen bases – caught stealing) ÷ at bats**

### Batting Average on Balls in Play (BABIP)

BABIP is a statistic measuring the percentage of plate appearances ending with a batted ball in play (which excludes home runs, walks, and strikeouts) for which the batter is credited with a hit. In other words, when Player-X hits the ball in play, how often does he get a hit? Since a particularly high or low BABIP is usually difficult to maintain, the stat is often used to explain fluky seasons by hitters. To some extent, it measures how lucky a player is getting when he hits the ball in play. BABIP uses the following formula:

**BABIP = (hits – home runs) ÷ (at bats – strikeouts – home runs + sacrifice flies)**

### Value over Replacement Player (VORP)

Instead of looking at Runs Created in a vacuum, VORP measures player performance against the “replacement level.” The term “replacement level” is meant to reflect a level of ability that is easily available to any team in a given league. In order to find Player-X’s VORP, follow these steps:

- Multiply the league’s average runs per out by Player-X’s total outs made. This gives you the number of runs a league-average caliber player produces.
- “Replacement Level” is defined as 80 percent of league-average (75 percent for catchers, because their defense matters more; 85 percent for first basemen and designated hitters, because their defense matters less). Therefore, multiply that league-average number of runs by 0.8 (or 0.75 or 0.85 if applicable). This is the number of runs you could expect a “replacement player” to produce.
- Subtract the replacement player’s Runs Created from Player-X’s actual Runs Created, and the result is VORP.

## Embrace the Revolution

Although they’re relatively new to the world of baseball stat analysis, the statistics on this list have already been widely adopted as performance indicators by scouts, coaches, sportswriters, and statisticians everywhere. Now that you have a basic introduction, hopefully you don’t feel too overwhelmed by the Sabermetric Revolution.

Basically, the goal is to evaluate baseball as objectively as possible. And although it’s never a good idea to worry about your stats as a player, keeping up with the trends of the game allows us to be more well-informed. Plus, next time you’re struggling at the plate, you can impress your coach by blaming it on a low BABIP!