baseball Attack Angle

The Blast Motion sensor provides for two different types of angles at contact. One is the attack angle (AA, side view) and the other is the vertical bat angle (VBA, front view). Both are extremely relevant to the swing as it moves through space, but with different attributes, characteristics and implications. This article is about the attack angle, a topic with a dearth of information out there.

A few days ago, Patrick Jones of Patrick Jones Baseball Podcast interviewed Matt Tanner from Blast Motion. It was an excellent interview because Tanner (for the first time that I am aware of) disclosed several pieces of information about MLB players and their swing metrics derived from the Blast Motion sensor. He disclosed several MLB averages, including:

- Attack Angle – 8 degrees
- Rotational Acceleration – 17g
- Early Connection – 92 degrees

Given the focus of this article, I should note that Tanner also added that no one, “no one” in the MLB has a negative attack angle. Imagine that, with all the talk about swinging down, up and everything in between, and A Rod telling the world that he swings down (even though he doesn’t), Tanner doesn’t know of a single MLB player that has a negative attack angle at contact.

On the other hand, in a recent article by Driveline Baseball titled “Pairing Blast and HitTrax Data”, among other topics, they listed their in-house AA results by level as follows:

👉 High School AA – 1.12 degrees
👉 College AA – 9.95 degrees
👉 Pro AA – 8.34 degrees

Two different sources have now disclosed an AA of 8 degrees +-, at higher levels of the game.

Now, let’s switch gears quickly and review pitch descent angles. In his article titled “Optimizing the Swing” in The Hardball Times (November 11, 2015), Dr. Nathan listed the following pitch descent angles on a fastball and a curveball (based on typical major league pitches from the PITCHf/x database):

I believe Dr. Nathan selected those two types of pitches, knowing full well that one is on the low end of the range, while the other is on the high end. If we put the two pieces of information together visually, this is what it looks like:

Here is the data listed numerically, with the average attack angle tucked in, right between the higher and lower descent angles. By the way, this is not an accident! This is evolution… Lol!

- Fastball Descent Angle: 6 degrees
  - MLB Average Attack Angle: 8 degrees
- Curveball Descent Angle: 10 degrees

Now, an average AA of 8 degrees in this case can be misleading. The standard deviation on these angles can be high, relative to the number itself. Our own studies with college-level guys shows an average standard deviation of approximately 4 degrees.

Let’s make a leap and say as players advance levels and solidify movement patterns that the standard deviation comes down a bit, perhaps closer to 3 degrees. This would imply that at -1σ to 1σ, the AA would be a range of 5 to 11 degrees.

There are two takeaways from this information:

a) After 100+ years of baseball, millions of swings,hits ‘n pitches, major league players swing in that range because that’s where they survive. With pitch speeds coming in at 80-95 mph, the human body knowing the task at hand is simply doing the best it can to compete. So, the number has parked itself right in the middle of the incoming!

b) Since there isn’t a single ball player today that has trained for swinging in a range of angles, most players that have made it to the BIGs are the ones that already swung in and around the range. The system has weaned out the guys with the low numbers. The ones with higher AAs better be hitting the deep ball often, because it might be difficult to stay on plane for them. Are there outliers? Freaks? Always! But you won’t know if you’re “one” until you get there.

Let me go one level deeper. Let’s say you’re a high school player with an average AA of 5 degrees. Given -1σ to 1σ AA of 4 degrees referred to earlier, your STD range is likely -1 to +9. Given the likelihood that pitch descent angles you’re facing in high school are higher than those listed above (due to lower pitch velocity), it won’t take much before you’re completely off plane with incoming pitches. You might hardly ever be “on plane” with a curveball coming in at 10 degrees or higher.

I totally recognize that a few degrees don’t mean a whole lot in the scope of many things. But in a game of inches, we’re talking milliseconds and millimeters when we talk hitting.

Closing Comments

Hitting coaches can keep talking about swinging down all they want. Alex Rodriguez can tell the world to swing down as he did in a recent video. Feel or real, whatever you need to do! Do it. But swinging downward or swinging anywhere near neutral “at contact” is a mechanical flaw.

Moral of the story… Get TESTED. Sub-optimal AA issues could be physical (subject of a later article) and/or mechanical. The longer you wait, the harder it will be to address it. The idea is not to match degrees. It’s to be in range.

By Bahram Shirazi (Co-owner RPP, MBA, BSEE)

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