How Vertical Approach Angle, o...

Paul Sewald was 30 years old and had pitched 147 1/3 innings in the major leagues when he washed up with the Seattle Mariners. He signed a minor-league agreement with Seattle prior to 2021 after being non-tendered by the New York Mets and sporting a 5.50 lifetime ERA. What his new instructors urged him to do went against everything he knew about pitching.

"They said when you throw the ball up in the zone, you're very successful," Sewald explained. "That was, like, an accident up until 2021 for me."

After making some adjustments in Triple-A, he returned to the majors in May and began dealing. But he was still throwing his fastball at 92 mph, barely half a tick quicker than when he was with the Mets.

If you've ever taken geometry, you'll understand and picture what VAA measures. It predicts the angle at which the ball is moving when it reaches the front of the plate using Statcast data provided on every pitch. Is the ball heading towards the dirt behind the plate? Is it still almost parallel to the ground when the batter tries to connect?

With the unusual exception of some submarine offerings, all pitches are traveling down, or at a negative angle, as they reach the plate after starting from an elevated mound. In terms of degrees, one end of the VAA spectrum is "flat," while the other is "steep." 

Sewald discovered he had one of those, maybe the most intense in baseball, after he began elevating on a daily basis.

"I kind of looked into it," he said. "And then I noticed that I was literally at the top of the leaderboard for people who don't throw underhand."

VAA is only one guiding light in the pitching universe's ever-expanding collection of statistics, but it's a particularly useful window into how clubs, coaches, and pitchers discuss their craft these days. There is no one method to be a successful pitcher, but there is a growing vocabulary that is being used to define the geometry of each pitch and, in turn, to mold the pitchers who throw them.

Understanding VAA as a pitching metric

VAA is not a simple figure that quantifies one item and tells you what is good and bad. At FanGraphs, Alex Chamberlain, who runs a public VAA leaderboard and has written extensively on the metric's implications, noted that VAA is important "because it captures the interaction of multiple pitch attributes at once."

These characteristics start with a pitcher's release point and finish with pitch placement. In the interim, velocity, spin, and pitch movement all play a part in determining the path of the ball at the critical time when a hitter may make contact. Sharp watchers track start-to-start changes to comprehend a pitcher's current strategy, and you can discover analyses of each individual component of a pitch.

How pitch shape can help shape pitchers

After years of trying to find a real ace and create the strikeouts required to dominate major-league hitting in the 2020s, the Minnesota Twins' pitching staff leads the league in strikeout percentage and K-BB% early this season. Ryan and offseason trade acquisition Pablo Lopez are both using modified arsenals that reflect a thorough knowledge of pitch form and how it pertains to them. When asked to define the combination of data and information utilized to determine a pitcher's best way ahead, Falvey laughed.

"There's a lot of ingredients to make that soup," he continued, naming spin, spin axis, vertical movement, horizontal movement, and other things that everyone is talking about right now. "It's complex."

The joys of exit velocity are unlikely to ever be inspired by pitching stats, it is true. For those outside of major-league clubhouses or specialized training programs, many metrics will continue to be opaque. However, these figures are becoming more and more important instruments for nurturing and rewarding the abilities that generate the more traditional types of excitement.

Falvey stated, "The thing that occasionally irritates me when I hear folks talk about, oh, this must be cookie-cutter. It's not at all cookie-cutter, in fact, just the reverse. You want to ask, "How can we make you the best version of yourself?" while taking into account each player's mix, slot, profile, and velocity — you know how it all works.

And baseball has always been played in this way. Simply said, we're doing it with more tools now.