Using Vertical Approach Angle to Identify MLB Draft League Prospects

Vertical Approach Angle

As technology continues to make its advances in the world, the use of analytics has become prominent in all major sports, especially baseball. With new data collecting tools such as Trackman, Rapsodo, and Statcast, professional, collegiate, and even high school players have been able to use the metrics provided to learn new information about themselves they never knew before.

Many metrics such as pitch velocity, exit velocity, spin rate, release height, and extension have been around much longer than modern metrics such as vertical/horizontal break, spin axis/efficiency, and vertical approach angle (VAA). While all these metrics are important to the player, only one can be king and that is VAA.

What is VAA?

Vertical Approach Angle (VAA) is a new measurement and is defined as how steeply up or down the ball enters the zone, reported as an angle in degrees, as the pitch crosses the front of home plate. A negative VAA means the ball is sloping downward, while a positive VAA means it would be sloping upward. To throw a pitch with a 0 degree VAA, it would likely go over the catcher’s head. 

There are many factors that can produce an elite VAA. Vertical Approach Angle is very dependent on the pitch location. Generally, it is only used when observing fastballs. Breaking balls and other offspeed pitches have higher VAA’s because they are steeper pitches and work better low in the zone, but that doesn’t mean they should be neglected. Trackman defines the strike zone as 1.5 feet to 3.5 feet above home plate. So to divide the strike zone up it would be 1.5 feet- 2.16 feet (Lower Third), 2.16 feet- 2.83 feet (Middle Zone), and 2.83 feet to 3.5 feet (Upper Third). Understanding and utilizing a pitcher’s VAA is very important for pitch calling, as Four-Seamers are better in the Upper Third, while Two-Seamers are better in the bottom Third. Along with pitch location, Induced Vertical Break, Release Speed, Release Height, and Extension all are main influencers of VAA. Because VAA is the measurement as the ball enters the zone, the more positive the vertical carry of the pitch (IVB), the flatter the VAA is of that said pitch. As for release speed, the harder the pitch is thrown and the quicker it is moving means there is less gravitational pull on it, which can create a rising fastball and a more effective VAA. Release Height and Extension are the last two major variables that contribute to VAA.

Two opposite MLB examples are Max Scherzer and Mike Fiers. They both have very effective VAAs in their own way. Scherzer has a low release height and great extension, largely due to how he drops and drives down the mound. This creates a “rising effect” of Scherzer’s fastball which induces a lot of swings and misses. Mike Fiers on the other hand, is the complete opposite. Fiers has a high release height and not as much extension as Scherzer, creating an “Iron-Mike” release and leading to a steeper VAA. While Fiers has a steeper VAA, that does not mean he can’t be effective. Steeper VAA’s are successful when located in the bottom third of the strike zone. 

The Importance of VAA

There are very few measurements that can correlate to success at the next level, but the ability to miss bats will always remain at the forefront for pitchers. Teams have now begun targeting pitchers with flatter VAA’s because they seem to be the guys with the best pure stuff. Each level's average VAA, spin rate, velocity, and movement patterns don’t change when you go from high school to college to professional ball, while whiff rate and opposing batted ball profiles do. 

As discussed prior, Four-Seamers with a flat VAA are generally best when located up in the zone while Two-Seamers/Sinkers have a steeper VAA and are better in lower parts of the zone. 

For the MLB Draft League, I took a sample of 4,000 Fastballs all located up in the zone (2.83 feet to 3.5 feet) and found out the swing and miss rate sorted by VAA. Here are the results:

VAA ranges are classified as Elite, Above Average, Average, Below Average, and Mediocre from top to bottom. The MLB Draft League is largely made up of collegiate athletes and some High School Players. The average VAA on a Fastball up in the zone in College Baseball this year was -4.9 degrees which is also the average for the Draft League. After seeing the league as a whole, let's look at some players that are separated from the rest.

Below are the leaderboards for Whiffs on Fastballs up in the zone, as well as leaderboards for Max and Average VAA on Fastballs up in the zone:

As the season comes to a close and the MLB Draft approaches, there are a few names who have set themselves apart from the rest. Pitchers such as Wesley Scott (WSP), Hayden Harris (FRE), Jacob Peaden (WSP), Justin Stewart (TRE), Riley Gowens (WSP), Duncan Davitt (MV), and Jonathan Pintaro (FRE) have all the intangibles to become an elite pitcher at the next level.

They all combine a tall frame with a low-to-mid 90s FB, high spin rate, an above average IVB, low Release Height, and great Extension to create a Vertical Approach Angle that plays extremely well up in the zone. 

Conclusion

Vertical Approach Angle is becoming one of the more important metrics in regards to pitching. The players and coaches who use it really understand how it is more of a location-dependent metric unlike Velocity, Spin Rate, and Vertical/Horizontal Break. VAA is very useful for players to understand what their metrics are because it can improve a pitcher’s performance by changing their plan of attack. If a pitcher knows he has a flatter VAA, he now knows he can attack up in the zone effectively and vice versa (steeper VAA, effective down in the zone). As the draft approaches, we will see how much more emphasis teams begin putting on Vertical Approach Angle as players start getting taken off the board.