The AZ Snake Pit Statcast Primer

Warning, this article contains large pictures and is best viewed on a computer instead of a mobile device.

Exit velocity (among other things) has become a huge part of the baseball world as we know it. It’s also something that’s been picked up steadily by the everyday, regular fan, not just the sabermetric/analytical baseball nerds. What a lot of fans haven’t realized, yet, is how easy some of this data is to gather. With that in mind, I’m going to give a very basic walk through of how to collect data through Statcast. I won’t touch into many of the various deeper things that Statcast can do, but I’ll point out what I think are the basics such that any fan can look up exit velocity on their own.

This article is geared towards people that haven’t used Statcast to search for data before. If you’re already experienced in searching for data within Statcast, this article should be very familiar to you.

What is Statcast?

But let’s start at the beginning. What is Statcast? Per the MLB website:

Statcast is a state-of-the-art tracking technology that allows for the collection and analysis of a massive amount of baseball data, in ways that were never possible in the past.

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At its heart, Statcast is a combination of two different tracking systems -- a Trackman Doppler radar and high definition Chyron Hego cameras. The radar, installed in each ballpark in an elevated position behind home plate, is responsible for tracking everything related to the baseball at 20,000 frames per second. This radar captures pitch speed, spin rate, pitch movement, exit velocity, launch angle, batted ball distance, arm strength, and more.

That might be too complicated; basically, Statcast combines Doppler radar with two high definition cameras to track things not capable of being captured via a box score, such as pitch speed, pitch spin rate, pitch movement, batted ball exit velocity, launch angle, and more. In other words, it’s essentially used to capture the physics of baseball and turn it into simple numbers that we can analyze.

There is one important thing to note with Statcast: it was introduced to all 30 MLB stadiums in the 2015 season. Prior to that, the PitchF/X system was used to collect pitching data. This is an important distinction to note because the Statcast system will let you search all the way back to 2008. However, only data that was collected by PitchF/X is available in 2008-2014 so many things like exit velocity and launch angle are not available if you search during this time.

How do I get to Statcast?

This is pretty easy at a high level: just go to the website https://baseballsavant.mlb.com/

However, there is more to it than just that. There are five tabs at the top:

If you can’t view the above image, try this link.

For most users, the “Statcast Leaderboards” and “Statcast Search” are the tabs you will want to select. “About” gives a very brief summary of Statcast, “Daily Matchups” gives an interesting summary of hitter vs. batter matchups including batted ball data (e.g. exit velocity) but is not terribly useful as of yet, and “Applications” gives some other tools that are quite excellent but beyond the scope of this post.

Let’s start with “Statcast Leaderboards”. This is something that many people may already be familiar with. This leads to a very nice-looking leaderboard that gives the MLB leaderboard in barrels (by default) and gives you a few other things to select and quickly sort. Aaron Judge, JD Martinez, and Giancarlo Stanton (except this year!) like to frequent the top of this leaderboard:

If you can’t view the above image, try this link.

If you look above the table, you will also see some other leaderboards: Sprint Speed, Catch Probability, Outs Above Average, Pop Time, and Expected Stats. These are all pretty fun to play with and simple to use as well. But the theme of these leaderboards is that they only let you play around with the few simple headers that they have in each table and you have no way to add in splits for more detailed inquiries. But in a pinch, they can be very useful and they are neatly organized for a good visual experience.

So what if I want a little more detail?

And this is where we get to the “Statcast Search” tab and the main theme for this article. When you click this tab, a screen with a bunch of options will open. This page can be very daunting and if you click the wrong thing, it can be extremely difficult to get to what you want. However, to make things simple, I have taken a screenshot and added some MS Paint wizardy to narrow down to the basics:

If you can’t view the above image, try this link.

Let’s take a look at the red boxes (numbered in blue):

1. Player Type: This is an important starting point as it affects what you see in field 6 (Sort By). Do you want pitching data or batting data? These are your only two options, so start here.
2. Season: What season(s) of data do you want to look at? You can select one or several seasons from 2008 - 2018. Keep in mind what I said above: only PitchF/X data is available prior to 2015 so if you’re looking for batted ball data, keep it to 2015 - present.
3. Game Date (optional): There are two fields here: the one on the left is “Game Date greater than or equal to” if you want to search AFTER a specific date and the one on the right is “Game Date lesser than or equal to” if you want to search BEFORE a specific date. You can use both to narrow the dates to a specific region if you choose. This field is purely optional; only use it when you don’t want to look at a whole season’s worth of data.
4. Team (optional): Pretty self-explanatory - select one or more teams that you would like to look at it. This field is again optional only if you’re trying to look at specific teams for data (such as the Dbacks).
5. Group By: This is where things get a little tricky but this is extremely vital to getting the search that you want. Whatever you select in the “sort by” field will then be presented based on what you select here. There are several options in this field and I will break them down further below.
6. Sort By: This is the field where you actually select the data that you’re looking for, e.g. exit velocity. Recommended stats to look at: xwOBA, xOBA - xwOBA, avg. pitch velocity, avg. spin rate, avg. exit velocity, avg. distance, and avg. launch angle (note that “avg.” will drop off if you’re searching by event). There are many other categories here to pick from if you want to play around with more, but they can get a bit more complicated and/or useless unless you set up a meaningful search.
7. Batters/Pitchers (optional): This is where you select individual batters or pitchers to pull data for. Don’t select the “team” field if you plan on using this field. You can select as many players as you want or just one, depending on your search.

With these seven fields, you can begin to use Statcast rather effectively to answer many of your batted ball questions and inquiries on your own! Once you use this a few times, it starts to make more sense in how the Statcast Search operates. You can end up with some really detailed information with the search fields available to you. I encourage anyone that’s interested to dive further into Statcast and become a better user at their own pace.

“Group By” Fields

As promised, here is a breakdown of the “Group By” fields:

• Player Name (default): This takes either the average or the raw total (depending of the stat) for the splits that you have selected above. So, if you have “pitches” (which is selected by default), it will give you the total number of pitches that each player in your search field saw during the time frame you selected. If you choose something like “exit velocity”, it will give you each player’s average exit velocity during your selected time frame.
• Player & Game Date: This is similar to above except instead of grouping into a large sample across your entire time period (say one full season), it will break it down by both player name and game date, so each player would have up to 162 different days worth of stats, depending on how many games each player played that season. These lists can get long.
• Player & Year: This is again similar to the first category but only useful when you’re looking at more than 1 season’s worth of data. Instead of combining stats across all selected seasons, it will break it down by each player and each season. This can be useful for seeing how a particular player has changed throughout the years.
• Player & Event: BE CAREFUL WITH THIS ONE. I only recommend this field if you’re looking at one player or one game or you have advanced tools able to parse and sort huge data fields. In Statcast, each plate appearance and/or batted ball is treated as a separate event. If you want to see how hard each of Pollock’s three home runs were last night, this is the field that you want to use. But if you do a league-wide search of exit velocities with “Player & Event” selected across multiple seasons, you’re going to get a search that takes a LONG time to complete and comes back with literally hundreds of thousands of data points. This can break your browser.
• Team: Instead of groups by player, it groups by team. Useful in limited situations.
• Venue: Same as above but instead by ballpark. Useful in limited situations.
• League: Useful for looking at the league as a whole, with whatever criteria you narrowed down in your search fields. Useful in limited situations.

An example search looking at the exit velocities for last night’s 8-5 victory over the Dodgers (D-backs only)

So, let’s start with an example that takes a bit of most of the things above. Let’s look at the exit velocities for each batted ball by the Diamondbacks in last night’s game. By default, it will sort from hardest to softest (I didn’t highlight this field but you can change this in the “sort order” field).

First, the search parameters:

If you can’t view the above image, try this link.

Hopefully this was pretty straightforward for you. I changed “Player Type” from “Pitcher” to “Batter”, selected 2018 as my season, set the end points of my two game dates to 2018-04-30 so it only selected that game, selected “D-Backs” as my team, chose to group by Player & Event to get each batted ball separately, and chose “Exit Velocity” as the stat to sort by.

And here are the results!

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What an interesting list. The top 8 hardest-hit balls from last night’s game included 2 by AJ Pollock, 2 by Jeff Mathis, 2 by Zack Greinke (lol), 1 by Nick Ahmed, and only 1 by Paul Goldschmidt. Baseball is a crazy game, isn’t it?