Over the past few days, I’ve been asked the same question multiple times:

“Why are pitchers who stay more upright, without a flatback finish and with less extension, often primarily changeup and sinker pitchers — and why do they have so much success with those pitches?”

It seems this question came up after a post on social media. For me, though, the answer is obvious — and actually the most natural thing in the world. At #BaseballActionID and with our new #MotorBall, we’ve known this for a long time: it all comes down to the natural blueprint of the pitcher.

Walking Top Pitchers → Upright Release + Supinator

Walking Top pitchers are supinators.

Their motor blueprint leads them to naturally stay more upright through the delivery. As a result, their release point stays closer to the body (less extension).

👉 This has nothing to do with conscious posture adjustments. It’s simply the outcome of their preferred coordination.
👉 And because they are spinners, their natural arm action aligns perfectly with pitches that thrive on spin deception and arm-side movement.

Why Changeup & Sinker Fit This Profile

Change-up

• Supinators naturally delay pronation.
• That delay creates the perfect late-release effect: the pitch looks like a fastball out of the hand, but arrives slower with extra fade.
• The upright release + shorter release point reinforce that fastball illusion.

Sinker

Supinators apply more pressure through the ulnar side of the hand (ring finger/pinky).

• Supinators apply more pressure through the ulnar side of the hand (ring finger/pinky).
• This produces natural arm-side run and sink.
• Because they don’t reach as far forward, the ball also comes in with a slightly steeper angle, which exaggerates the drop in the hitter’s perception.

Correlation / Logic

• Upright release → shorter release point → more deception (instead of a disadvantage).
• Supinator preference → ideal for pitches that rely on arm-side run and late pronation (changeup, sinker).

Their arsenal is not random. It’s a direct outcome of their natural motor preference + release ‘mechanics‘.

Conclusion

What is often labelled on social media as a flaw (“lack of extension,” “no flatback finish”) is, in reality, simply the natural blueprint of that pitcher.

Walking Top pitchers are supinators. That determines not only their upright finish, but also why their most natural and successful weapons are the changeup and the sinker.

And here’s the key:

👉 When you know a pitcher’s blueprint, you can even align his pitch grips with his preferences. Once everything is in line — movement, release, grip — you unlock the best possible output and the best possible data for that individual.

Instead of looking outside-in (chasing data first, then forcing mechanics), we flip the model: inside-out. Understand the natural blueprint first, align everything to it, and the data will follow — better, more consistent, and more sustainable.

⚾️ This is exactly what #BaseballActionID and #MotorBall are about: not chasing averages, but maximizing the unique potential of every pitcher.