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Next time you watch a baseball game, pay attention to the stat lines that pop up on the bottom of the screen when a hitter steps to the plate. What three stats are most often displayed?
Batting average, home runs, and RBI.
While these three categories may be of particular interest to the general baseball audience, there is another statistical category that has gained popularity among scouts, coaches, and front office employees:
On-Base Percentage OBP.
A player’s on-base percentage tells how often a player earns his way on-base via hits, walks, or hit-by-pitches. Fangraphs.com states that a good on-base percentage should be about 60 points higher than a player’s batting average. For example, a .300 hitter should have at least a .360 on-base percentage.
While it has gained attraction from those in the inner baseball circle, there is still some confusion about what it is, what it truly means, and how important it is among some fans in the baseball world.
How is On-Base Percentage Calculated?
Like calculating batting average, on-base percentage requires division. However, there are different stat categories included in the calculation of the two.
Batting average is calculated by simply taking the total number of hits and dividing it by the total number of official at bats.
Hits
_________ = BA
At-bats
On-base percentage is calculated by taking the total number of hits, walks, and hit-by pitches and dividing it by the total number of plate appearances.
Hits+Walks+Hit-by-Pitches
_________ = OBP
Plate Appearances
Remember, walks, hit-by-pitches, and sacrifices do not count as at-bats, but they do count as plate appearances.
Why OBP?
On-base percentage became more popular among scouts, coaches, and front office managers in the early 2000s thanks to a guy named Bill James. James is a baseball historian and writer who developed a system in which he termed SABRmetrics.
James defines SABRmetrics as “the search for objective knowledge about baseball” (sabr.org). It uses statistics to understand more about the game of baseball and what makes a player and teams more valuable.
One of the most valuable statistics in SABRmetrics is on-base percentage. Basically, runs cannot be scored unless players are on base. Batting average does not always tell the whole story because it does not account for all of the ways a player can reach base.
In James’s mind, a walk or a hit-by-pitch is as good as a hit because it puts the player on base giving him the same chance to score a run as if he reached by a hit.
This mindset is more common in today’s game than it was in the 80s when he first began his research. It took a while for it to gain traction in the scouting and managing realm of the game.
This famous scene in the movie Moneyball depicts the emphasis small market teams like the Oakland A’s began placing on on-base percentage when evaluating players.
What is a Good On-Base Percentage in the Major Leagues?
According to fangraphs.com the average on-base percentage so far in the 2021 Major League Baseball season is .315. As a whole the league is hitting at an average of .240, so their goal of having an on-base percentage of at least 60 points higher than batting average is holding true so far in the big leagues.
This year’s on-base percentage is down from 2020. Last season, the average OBP was .322 compared to a batting average of .245. In 2019, the last full 162 game season, the league’s OBP was .323 with a batting average of .252.
From the mid 90s to early 2000s, average OBP in the Major Leagues hovered anywhere from about .333 all the way up to .345 in the 2000 season. Coincidentally, this is when SABRmetrics first started making its rounds among front office staffs around the league.
For a more in-depth look at on-base percentage through the years, as well as several other statistical categories, visit Fangraphs seasonal leaderboards chart.
What is a Good On-Base Percentage in High School Baseball?
Like most statistical categories in high school baseball, a good on-base percentage depends on the competition level of that state or region. The talent level in high schools across the country varies making it difficult to nail down a specific number for all high schoolers.
With that being said, fangraphs’ rule of thumb of 60 points higher than the player’s batting average was designated for professional hitters. This number may be a little low for high school players.
A good high school hitter will likely have about an 80 point difference (at the least) in his batting average and on-base percentage for various reasons.
For one, pitchers’ command of the strike zone in high school baseball is not as good as Major Leaguers. A good hitter has a good eye for the strike zone and will take more pitches; therefore, this will result in more walks increasing the player’s on-base percentage.
Second, really good hitters often don’t get good pitches to hit in RBI situations in high school games. Coaches and pitchers sometimes like to “pitch around” good high school hitters. This means that while they may not intentionally walk them, they will throw them pitches outside the zone hoping the hitter will chase them.
Third, Bill James’s philosophy (discussed previously) has even made its way to many high level high school programs. While it is more difficult for them to implement SABRmetrics to the same degree as MLB organizations, many have still adopted the philosophy and many good players have bought into it.
It is not uncommon to see a high school player with an on-base percentage of well over .500. Batting averages in high school baseball tend to be higher, therefore, making on-base percentages higher as well.
Again, it is important to reiterate that setting benchmarks for high school players is difficult due to the wide range of competition levels. Knowing the area and the talent level of the players in it is key to setting statistical goals for high schoolers.
What is a Good On-Base Percentage in College Baseball?
In college baseball, the competition level is closer to the Major Leagues than high school, but there is still enough difference from conference to conference that it is difficult to set a one size fits all standard for statistical categories.
For example, the Southeastern Conference (SEC) is a much stronger conference than the Ohio Valley Conference (OVC). Are there teams and players in the OVC that can compete with SEC teams and players? Absolutely. But we must judge them based on the conference in which they play.
In most levels of college baseball, many teams have adopted the “a walk is as good as a hit” mentality started by James, so OBPs around the country have increased in college baseball.
A player’s on-base percentage is something that professional scouts analyze when evaluating a college player for pro baseball.
For teams that have fully invested in SABRmetrics, a college player with a high batting average and on-base percentage that is less than 50 points higher than the batting average may be crossed off their list. This would classify the hitter as a “free swinger”, and analytics driven teams don’t value those players as much.
When it comes to on-base percentage, it all comes down to comparing it with the player’s batting average and the quality of pitching that they face. Using fangraphs’ 60 points rule of thumb is typically appropriate for the college level because the competition level is much greater than high school.
Frequently Asked Questions
Does reaching base on an error count toward a player’s OBP?
No, if a hitter reaches on an error, it counts as an out in the books and does not help his OBP. This is because OBP is supposed to tell how often a player earns his way on base. The idea is that reaching base because of a fielding error is more to do with the defense’s mistake and that the hitter did not earn his way on base.
What is the highest OBP in Major League history?
In 2004, Barry Bonds had an eye-popping OBP of .609. He also holds second place on the list with a .581 OBP in 2002. He hit 45 and 46 home runs those years and had batting averages of .362 and .370 at the ages of 37 and 39. Whether those numbers are inflated is up for debate.
Who has the highest career OBP in Major League History?
Ted Williams retired with a career OBP of .481. This is eight points higher than Babe Ruth’s .437 which gives him second place on the career list. The player from the modern baseball era with the highest OBP is Barry Bonds who sits at .444 for his career.
Is OBP considered when giving out awards at the Major League Level?
OBP is sometimes taken into account when a player is being considered for awards such as Most Valuable Player and Rookie of the Year, but batting average, home runs, and RBI (the triple crown numbers) are typically viewed as the main statistics that factor into these awards.
See Also:
What is OPS in Baseball? (Detailed Explanation)
What is the Highest Scoring MLB Game in History?
How Many Players Are on a High School Baseball Team?
What is a Walk Off Home Run? (Explained)
