OPS and OPS+ Definitions
OPS and OPS+ are statistics used to evaluate offensive performance. OPS simply stands for On Base Plus Slugging, while OPS+ is a scaled version of that same idea. You will see OPS quoted during baseball broadcasts from time to time, as it has become relatively well-known, while OPS+ remains present mostly in the sabermetric community.
OPS is nothing more than adding together on base percentage and slugging percentage, making it a relatively simple stat, as far as ‘advanced metrics’ are concerned.
OPS+, on the other hand, is a bit more complex, as it considers park factors and league factors.
While both of these are rate stats, OPS is expressed in raw terms while OPS+ is scaled to 100 as league average.
The Concept of OPS and OPS+
The concept behind these statistics is that some of the traditional batting statistics – such as batting average and slugging percentage – don’t quite do a good enough job of representing a player’s contributions at the plate. OPS and OPS+ aim to offer a more realistic representation of performance by including elements that are overlooked in basic statistics.
Let’s walk through an example to see how OPS can offer a more informative look at player performance than something like batting average. During the 2018 season, Jose Altuve and Mike Trout, two of the best players in baseball, had similar batting averages. Altuve batted .316 for the year, while Mike Trout batted .312.
On those numbers alone, you might be tempted to think that they were similarly productive at the plate, but that was not the case. When looking at OPS, we see Trout well ahead, with a 1.088 mark compared to .837 for Altuve (which is still very good). Trout reached that 1.088 number with a .460 OBP and a .628 SLG. For Altuve, those numbers were .386 OBP and .451 SLG. Thanks to significantly higher numbers in both on base percentage and slugging percentage, Trout was able to set himself apart. In fact, his 1.088 OPS was the highest for any qualifying player during the 2018 season.
Why are OPS and OPS+ Important?
These are important statistics because they can be thought of as a gateway to advanced statistics. Nearly every baseball fan knows and understands batting average, on base percentage, and slugging percentage. However, getting those fans to make the jump to advanced stats can be difficult.
Some advanced metrics are hard to understand for even the most dedicated sabermetricians, but with OPS, the intimidation factor is reduced, helping fans take a step away from traditional stats and toward other metrics. In fact, these two stats can work together to help fans make that transition.
For example, someone might get started by learning about OPS. Given that it is simply on base percentage and slugging percentage added together, it should be pretty easy to learn how this stat works.
From there, introducing OPS+ will be a little easier, and will help the individual pick up the idea of stats that have been scaled to use 100 as league average. There are a number of other stats that work this way, such as wRC+, so getting started with OPS and OPS+ can be helpful. Also, OPS+ includes park and league factors, which is another concept that appears time after time in advanced metrics.
How are OPS and OPS+ Calculated?
For OPS, the calculation could hardly be any easier. As the name indicates, simply add together a player’s on base percentage and slugging percentage to arrive at their OPS. So, if a player has a .350 on base percentage and a .450 slugging percentage, their OPS would be .800.
With OPS+, things are far more complicated, because of the inclusion of both park and league adjustments. Your best bet is simply to look up this statistic when you would like to use it, which can be found on Baseball Reference.
What are Good OPS and OPS+ Numbers?
For OPS, anything north of .800 is going to signal a player who has had a good offensive season. Going above .850 will usually put a player within reach of All-Star status, depending on what other skills that player might bring to the table (such as defense and baserunning). Players with an OPS above .900 are some of the best hitters in the game, and those managing to break 1.000 are true superstars.
When looking at OPS+, the key is to remember that the statistic is scaled to set 100 as league average. So, a player with an OPS+ above 100 is a better than average hitter for that season. Recording an OPS+ above 120 is an excellent effort, and only a few players will be able to get into the 150s and beyond.
To provide some additional context for these statistics, let’s look at top performances by some of the best hitters in the game. This first chart includes the top ten OPS performances for the 2018 season.
Next, let’s look at the top-ten players in OPS+ for the 2018 season.
What are the Problems with OPS and OPS+?
The glaring problem with OPS is that it values on base percentage and slugging percentage equally, when that should not actually be the case. OBP is significantly more valuable to producing runs than slugging percentage, yet the two are simply added together without any weighting in this calculation. This is one of the motivations behind the development of wOBA, as that statistics properly weights the various components correctly.