Statcast 101: Plate Discipline Metrics

Chris Clegg breaks down plate discipline metrics, how to use them , and what they mean.

Statcast data has changed the game and the way we evaluate players, well at least some people. The baseball community is pretty split on what matters when it comes to evaluating players as you’ll often hear a wide variety of opinions from just watching a Major League broadcast on television.

Looking for an edge is something we all do, whether it be in life, fantasy baseball, or actual MLB organizations. Finding and creating new metrics is constantly happening in the game we love, so seeing what matters and what doesn’t, especially when it comes to advanced metrics is important.

When doing offseason research, Fangraphs and Baseball Savant should both be go-to resources for you. But what if you find a metric on there that you just are not sure what it means? This article series will help answer those questions for you as we dive into statcast and other advanced metrics that you can use to analyze a player for fantasy baseball.

Read Part 1: Exit Velocities and Hard-Hit Rates

Read Part 2: Barrels, Launch Angle, Sweet Spot

Read Part 3: Expected Stats

Well, this feels slightly like cheating. I am continuing the Statcast 101 series but talking about stats that are not direct statcast metrics. Despite plate discipline not being technical statcast data, they are still valuable metrics for evaluating hitters. Most of the numbers we will discuss today can be pulled from both Fangraphs and Baseball Savant.

Baseball Savant and Fangraphs are both likely a resource you use when evaluating players. You may see stats on those websites that you do not know what they mean. This article series has the intention to help you learn more about specific statcast data and other stats and how you can use that data to analyze players for Fantasy Baseball. It is important to note that a player’s statcast profile does not paint the entire picture. It is just another tool in the toolshed. So, let’s look at a couple of stats and how they are practical for Fantasy Baseball. So, let’s talk about some plate discipline metrics and what they mean.

Plate Discipline Metrics for Evaluating Hitters

Take a look at the plate discipline profile on Fangraphs. You can probably guess that this is Juan Soto. Soto has elite statcast metrics, as we have discussed in previous articles, but what about his plate discipline? To no surprise, most of Soto’s metrics come out high-end compared to the league average, which you can find in the shaded rows and you can make appear by clicking Averages on the top line of the Plate Discipline metrics. Looking at this profile on Fangraphs for hitters is very important. But what do all these stats mean? Let’s talk about them.

Contact Percentage

One of the first metrics I look at is contact percentage. Contact percentage is the number of pitches in which contact was made divided by all swings. If a hitter has a low contact rate, it usually leads to inconsistent, streaky performance. Nearly every hitter with a low contact percentage is usually a streaky performer.

Fernando Tatís Jr. is the rare exception. His 69.5 percent career contact rate is well below average, but we know that Tatís is still an elite performer despite that. Some hitters can get away with lower contact rates as we have seen with players like Tatís and Aaron Judge, but usually, I want a hitter to at least be near 72 percent overall.

The league average contact percentage last season was 76.4 percent. Anything above 80 percent is good, while 90 percent and higher is considered elite. Ideally, you want to draft hitters on your team that have above-average contact rates or better.

Zone Contact Rate 

Zone contact rate is another helpful metric that builds on the overall contact rate. It is sometimes called Z-Con rate, which is the number of pitches in which a hitter makes contact on pitches inside the strike zone divided by the hitter’s total number of swings in the zone.

Not every hitter with bad contact rates also had bad zone contact rates. Jeremy Peña stands out for having a zone contact rate of 88.2 percent, but just an overall contact rate of 73.8 percent. The league average on zone contact was 85.4 percent in 2023. Eighty-eight percent or higher is a good zone contact rate, but getting above 93 percent puts you in elite company.

Swinging Strike Rate

Swinging strike rate or SwStr% is how often a hitter swings and misses divided by all pitches. The league average in 2023 was 11.1 percent, which is right in line with the previous five seasons. The picture above shows that Juan Soto posted an impressive 6.2 percent swinging-strike rate in 2023, which was the 22nd best in baseball. Several players posted swinging strike rates below four percent, including Luis Arraez, Nick Madrigal, and Steven Kwan.

Swinging strike rate has a strong correlation with contact rate. Mickey Moniak posted the highest swinging strike rate in 2023 at 21.9 percent which was nearly two percentage points higher than the second worst mark of Jose Siri at 20.2 percent. Javier Baez posted the league’s worst swinging-strike rate at 21.7 percent. Both those players has low contact rates at 64.3 and 61.6 percent respectively. Players with high swinging strike rates are some I tend to avoid with the exception of Luis Robert Jr, who checks in with the ninth-highest swinging strike rate in 2023.

O-Swing Percentage

O-Swing percentage, sometimes referred to as Chase Rate, is the percent of pitches outside of the zone that a hitter swings at. This stat helps us understand how good a hitter is at laying off bad pitches. The league average in 2023 was 31.9 percent.

Juan Soto checks in with a 20 percent chase rate, sixth lowest among all hitters in 2023, with Edouard Julien having the lowest chase rate at 17.2 percent.

If you are in an OBP league, be sure to look at O-Swing percentage as it can be helpful in identifying hitters who typically walk at a high rate. Also, hitters with a higher O-Swing percentage can fall into the category of poor contact. The correlation is not as strong here, but Mickey Moniak who we mentioned having the highest swinging strike rate has the second highest chase rate at 48.8 percent.

These plate discipline stats are the ones I find most useful. They all have a practical use for Fantasy Baseball stats. I hope you will dive into these metrics a little deeper and find players that may be solid targets in your drafts.