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.
Statcast Data and What It Means
We often hear someone refer to a player’s statcast page and say it is full of red or full of blue. Here is what they mean when they refer to the statcast page or bubbles.
In the picture above, you can see that Ronald Acuña Jr. ranks exceptionally well in every hitting category. When a player ranks well in a category, you will see color and a percentile. If a player ranks highly, that data set will be red. As a player fades toward the 50th percentile, that color will fade to neutral and eventually blue. A slider will be blue on the far extreme if a player ranks poorly in a category.
It is easy to look at a statcast profile like Acuña’s full of red and automatically assume that the player is good. Duh, Ronald Acuña Jr. is good, more like the best player in baseball good. The same can be said for a player with a lot of blue in his profile. While it is likely true, it is worth understanding what each stat means and how it correlates to actual stats that matter for Fantasy Baseball.
Here is a player profile that is not so red. This player has a 2024 ADP near 100 largely due to speed and stolen bases.
When you first get to a player’s profile on Baseball Savant, you will find a nice picture of the player with the player’s position, whether they bat/throw right or left, the player’s height, weight, and age. If you move to the middle of the page, you will see MLB percentile rankings. This list shows several different statcast numbers and their percentile rankings among hitters or pitchers. Finally, to the far right of the page, you’ll see a hitter’s spray chart on just batted balls that became hits.
If you scroll down on the player’s profile page, you will find a player’s stats for both the current/previous season and the player’s career. Then you see the statcast data. This is ranked on the sliders at the very top of the page. This view gives you a nice overlook at how a player may have improved or regressed each season.
Right below the statistics is a nice chart. The default view is the percentage of each pitch type a player saw in a season. The pitch types are broken down by fastball, breaking ball, and offspeed. The pitch tracking section below the chart shows how a player performed based on pitch type.
This chart is handy for a lot of things. If you can click into the drop-down box labeled “PITCH %,” you can change the input to a variety of statistics, including all statcast data. In most cases, I switch “PITCH GROUP” to “ALL PITCHES,” which provides an excellent overview of how a player has performed. You can look at a player’s performance over the season, month, or game. If you are a visual person like me, you will likely find this page section very useful.
This is all great, but how did we get here? How is this tracked? Well, I am glad you asked. This is a Hawkeye camera if you have ever seen one of these things at the ballpark. There are 12 of these around the ballpark to track everything that happens during a baseball game.
Starting in 2015, MLB began using statcast and tracking every little detail of the game. It began using TrackMan, but in 2020, they switched to Hawkeye which is shown above.
The possibilities here are endless, and every year, Hawkeye software gets a little better and is able to track more. The newest iteration in 2023 is bat speed for all players, which has a large correlation in power metrics.
Before we get too into the weeds with Hawkeye, let’s talk about a couple of metrics, what they mean, and how to use them.
Average Exit Velocity
Exit velocity is one of the more simplistic statcast numbers. Essentially, exit velocity is how fast, in miles per hour, a batted ball is hit. Average exit velocity is calculated by dividing the sum of all exit velocities by all batted ball events. Having a high average exit velocity is a skill a player can own. It means a player is hitting the ball hard and has a higher probability of positive results.
Average exit velocity has a high correlation with being descriptive of a player’s wOBA, Home Run percentage, ISO(Isolated Power equals Slugging Percentage minus Batting Average), and even batting average. Average exit velocity has the strongest predictive correlation with the future batting average when projecting a player’s future performance.
When testing it against max exit velocity, average exit velocity is more descriptive of the home run rate and home runs per batted ball event. Looking at home runs per batted ball event last year, we see an R2 of just .312 for max exit velocity versus .369 for average exit velocity. It is interesting because max exit velocity seems like it would be a better indicator of home runs.
Fantasy Implication
Average exit velocity can be useful for fantasy baseball when looking at a player’s performance and evaluating whether they are sustainable. Let’s say a hitter has a .185 batting average over the first month of the season but leads the league in exit velocity. It is possible they have gotten unlucky and could create a good buying opportunity from a fantasy standpoint. On the flip side, a player off to a hot start but has just an 85 mph average exit velocity could show a potential decline and be a good selling opportunity.
My studies show that in the juiced ball era, the average exit velocity did not matter as much. Another study found that MLB began juicing the balls after the 2015 season. The correlation between home runs and average exit velocity was lower in 2016 through 2020. Surprisingly, after the ball was “deadened” for 2021, the direct correlation between average exit velocity and home runs was higher. Who knows what MLB will decide with the baseballs in 2024, but one thing is sure. If it is a “deadened” baseball, you will likely see hitters with lower average exit velocities hit fewer home runs as we have seen the past few years.
Average exit velocity is not always the most valuable stat, but it does have its purposes. It is probably the most quoted statcast metric, but know what it is helpful for. Let’s take average exit velocity a step further.
Exit Velocity(Line Drives/Fly Balls)
Let’s travel over to Baseball Savant’s leaderboard page to look at a hitter’s average exit velocity, but only on line drives and fly balls. Because average exit velocity includes all batted ball events, weakly hit grounders can easily skew it. If you are looking to forecast a hitter’s power, exit velocity on FB/LD is more descriptive and predictive of a player’s power output.
To no surprise, Aaron Judge sits at the top here as he also has far and away the best average exit velocity in baseball. Some surprises on the list include Teoscar Hernandez and Jake Burger, who, when they lift, can get the most out of their power.
To find this on Baseball Savant, go to the statcast leaderboard and exit velocity and barrels tab.
Fantasy Implication
If you are looking to use average exit velocity to evaluate and project a hitter, I recommend using average exit velocity on line drives and fly balls. Studies have proven it is a little more sticky than general exit velocity. It does not matter how hard a player hits the ball if it is drilled into the ground. A player who hits the ball in the air and hits it hard is much more likely to have a better power output.
If you are looking for a more descriptive and predictive metric of future power output, average exit velocity on line drives and fly balls is the way to go.
Hard-Hit Rate
On Acuña’s profile listed above, you will see a hard-hit percentage. Statcast defines a “hard-hit ball” as one with an exit velocity of 95 mph or higher. A batter’s hard-hit rate merely shows what percentage of batted balls are hit 95 mph or higher. Why does this matter? Well, the 95 mph exit velocity threshold shows where things begin to matter. The chart below is from MLB.com and shows wOBA against exit velocity. You can see the trend.
In 2023, hard-hit batted balls produced a leaguewide .506 batting average, a 1.008 slugging percentage, and a .625 wOBA. On the flip side, batted balls hit below 95 miles per hour produced a leaguewide .221 batting average, a .261 slugging percentage, and a .207 wOBA. These statistics make it pretty clear there is a value in the hard-hit rate.
Last season, 21 hitters eclipsed a 50 percent hard-hit rate. You can find that leaderboard below.
Fantasy Implication
I have attached the 2023 hard-hit rate leaderboard above. Typically, players with a high hard-hit rate perform well across the board. Most of these hitters also go incredibly high in drafts. Outliers include Ryan O’Hearn, Maikel Garcia, and Joc Pederson. All have various reasons they are not high draft picks for Fantasy Baseball, but all have the upside to be solid contributors.
Using hard-hit rates to evaluate the legitimacy of a player’s performance is a great thing to do. Hard-hit rate also tends to stabilize year-to-year, so you can use it as a predictive measure as well.
Be on the lookout for more “Statcast 101” articles as we dive into what matters for hitting performance and using it to evaluate players.
Media References: Baseball Savant, MLB.com
