Pitch Design and Development… The Pursuit of Abnormal Movement

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

The article below is from a righty pitcher’s viewpoint.

A while back we wrote about a topic titled “What is Relative Movement? And Why is it Important?” (click here). This article looks to further refine that concept, and it’s a topic that all high-level pitchers should consider at all levels of the game.

We have now reviewed so many Rapsodo reports that we can pretty much predict a typical pitcher’s overall movement pattern as soon as we see his arm slot. Movement patterns are highly intertwined with arm slot. If you have a hard time seeing that, here is a correlation analysis we published last summer at RPP (click here for complete study):

With a Correlation Coefficient R (a measure of how strongly a pair of variables are related) of 0.71 across hundreds of data points, you can conclude a high level of correlation between arm slot and spin axis, or said differently the direction of movement.

Here is a more visual way of looking at this. Below are several slides from a study by Matt Lentzner (formerly a contributor to Baseball Prospectus). You can clearly see how movement patterns follow arm slots.  When you think about it, it makes total sense.

Above images courtesy of presentation by Matt Lentzner (click here).

Now that we have established that relationship, let’s quickly talk about a somewhat related topic.

A typical MLB pitcher with a 93-94 mph fastball has an average spin-rate of 2,200 rpm.  Players see this pitch just about every day of the week. It is perhaps the single most thrown pitch. So, the general thinking is, when MLB scouts are evaluating players getting away from the norm is a probably good idea.

Now, let’s apply to this concept to ball movement. Here is an overall movement pattern for several dozen typical HS pitchers (collected randomly from 35 players in our various programs).Following on the theme above you can pretty much determine the average pitcher’s arm slot from the above movement pattern. This arm slot is probably what’s considered to be ¾, along with a bit of shoulder tilt which moves the 4-seam slightly more towards 12:00 o’clock.  You can also clearly see the narrow band of movement.Now let’s talk about the fun stuff, abnormal movement.  Similar to spin-rates we discussed earlier, in order to be different and perhaps elite, you want to get away from the “norms”.  So, follow the arrows.

I can say with a high degree of certainty that norms exist at every level of the game where the vast majority of players move the ball similarly.

The above movement chart represents our experience with high school norms and the  following are our overall suggestions:

    • 4-seam – We generally recommend leaving the 4-seam alone. A typical pitcher has thrown that pitch so often that unless we have to, we generally recommend leaving it where it is. If the remainder of your arsenal is differentiated, you can possibly get away with a 4-seam with average movement.  Having said that, get stronger, throw harder and your spin rate will likely increase.  With that increase you can get more vertical lift on your 4-seam.
    • 2-seam – In order to increase the differentiation from a 4-seam, we highly recommend a sinker over a regular 2-seamer. We suggest you get as much lateral movement on that pitch as possible. Given how movement patterns shift, that will likely kill your 2-seam’s vertical lift, but the pitch should run inside on a righty batter as much as possible.
    • Change-up – Get away from the 4-seam and 2-seam, either laterally or vertically as much as possible (and obviously in velocity as well).
    • Slider – Create as much lateral movement towards glove-side as possible, like what Trevor Bauer did in 2018. If you’d like more info on this please see our article on sliders by clicking here.
    • Curveball – Create as much depth as possible and get outside the norms.

I’ll even take a leap and say these suggestions are probably valid at all levels of the game to various extent.

The idea is to expand the moment pattern from a narrow band to a wider one.  The following chart should provide a good visual on before- and after- movement patterns.

Having said all this, the location of your arm slot may put some limitations on how much and where you can expand your pattern.  For example, a side arm pitcher who physically can’t throw a 12/6 curve ball, might also have difficult getting a ton of vertical depth on it.  But he sure can develop a ton more lateral movement than most.

Moral of the story is… Find out the norms and get as far away from them as possible, it will make you Elite.

It’s really not rocket science, it’s just common sense.