What Does Statcast Bat Tracking Data Reveal About the Diamondbacks?

Since the advent of Baseball Savant and the Statcast metrics provided by that site, baseball fans have been granted an ever expanding view into what was previously the exclusive purview of scouts and coaches. That view has just been expanded significantly with the unveiling of the "Holy Grail": The Bat Tracking Leaderboard.

The first thing to know is that there are multiple components being measured. The most prominently displayed is Average Bat Speed, and a subset from that Fast Swing Rate. Those will be the most often quoted. But equally important are a hitter's Squared Up and Blast Rates. Finally, swing length helps point towards a hitter's profile when it comes to contact vs. power.

Fast Swing Rate

A player’s average bat speed is the average of his top 90% of swings. MLB average is 71.5%. A “fast swing” is 75 MPH+. 22.4% of MLB swings are categorized as fast swings.

The MLB average on fast swings 75 MPH or higher is .307 with a .603 slug, while the average on anything less than 75 MPH is .246 BA, .389 slug. Below is a table of the D-backs leaders in this category. Only players with 40 or "competitive" swings are included.

D-backs average bat speed | Jack Sommers

Squared Up Rate and Blast Rate

A swing’s squared-up rate compares how much exit velocity was attained compared to how much potential exit velocity was possible based on bat speed and pitch speed. A “blast” is a swing that squares up the ball and does so with a fast swing.

It's important to square up the ball, but the most valuable swings occur when the ball is squared up and the swing is fast, thus defined as a blast. The league average for swings defined as blasts is .545 with a 1.116 Slug. Compare that to a .171 BA and .221 slug for non-blasts.

Not surprising perhaps is Ketel Marte has been the leader in the blast category. Corbin Carroll ranking 3rd on the team seems incongruous. However one outlier result does not invalidate a metric and it may actually be a signal of better things to come for the struggling sophomore.

Swing Length

Swing length is a metric intended to identify if a batter has a short or long swing. The average swing length is 7.3 feet. There is a large range however. For example Giancarlo Stanton has an average swing length of 9.7 feet while Luis Arraez has an average swing rate of 4.4 feet.

On average a shorter swing results in higher contact rates and batting average but less power, just as you'd suspect. Shorter swings generate a .258 BA and .359 slug while longer swings have a .235 BA but .422 slug.

Conclusions

As these new metrics have been unveiled there has been a rush on the part of analysts to parse the data and figure out what it all means. There is a lot of work to do but a few takeaways from a Diamondbacks perspective.

Ketel Marte's combination of swing speed and ability to square up the baseball are yet more confirmation of what we already know. He's an excellent hitter who can both make contact and drive the ball.

Corbin Carroll has a short, compact swing to the ball, but generates a lot of bat speed. Once his bat finally gets going, it would not surprise to see him hit for a good batting average again with a lot of gapped balls, but the home run power may continue to stay well behind last year's output.

The combination of a long swing with slower than average bat speed, and below average rates squaring the ball up are what we are seeing with a couple of key right-hand veterans in Lourdes Gurriel Jr. and Eugenio Suarez.

We don't know yet how sticky these metrics are, and how easy is it for a player to change these profiles. But there must be at least some level of concern that their early season struggles may persist.

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