What “Rise” Looks Like on a Fastball

If you’ve ever watched even maybe one baseball game in your entire life, you’ve probably heard the term “rising fastball” used by a broadcaster, coach, or player. In point of fact, insofar as gravity is a thing that we have on earth, the notion that a fastball can “rise” is a misnomer. Like any object, a baseball is drawn toward the earth at 9.8 meters per second squared.

If you’ve ever made your way to a pitcher’s PITCHf/x page here at the site, however, you might’ve noticed that, indeed, pitchers are credited with positive (or “rising”) horizontal movement on many of their offerings. The league-average vertical movement for most pitch types, in fact, registers as positive.

While these two facts appear to contradict each other, they actually don’t. The PITCHf/x numbers for vertical movement one finds here — and at sites like Brooks Baseball and Texas Leaguers — are presented not as absolute movement, but movement relative to a spinless ball. When we see that a league-average fastball has 8.8 inches of postive vertical (i.e. Y-axis) movement, what that means is, is that the league-average fastball drops 8.8 inches fewer than a ball without backspin.

The intent of the present post, however, is neither to discuss the finer points of physics nor to make a particularly salient point about or using PITCHf/x. The author has expertise in neither. What the author does know about is how to make a GIF, which is what he (read: I) has/have done.

Specifically, what I’ve sought to do is to give readers a sense of what “rise” looks like on a fastball — if it looks like anything, at all.

To do this, I first consulted the PITCHf/x leaderboard to find the right-handed pitcher with the most positive vertical movement on his four-seam fastball. The reason why I chose the right-hander with the most vertical movement has to do with the next couple of considerations. I wanted to also find (a) a pitcher who had pitched in front of one of the league’s straight-on center-field cameras and also (b) another pitcher throwing a fastball with something close to league-average vertical movement on the same camera.

One finds in our leaderboards that, among right-handers with at least 10 innings thrown, Tampa Bay’s Joel Peralta has the highest average vertical movement, at 12.2 inches. One finds, moreover, that Peralta threw in front of Miami’s straight-on center-field camera on June 8th of this year — the same day that teammate Jeremy Hellickson, whose fastball averages 8.8 inches of positive vertical movement, also pitched.

With all that settled, I set out to find a four-seamer thrown by each pitcher during that game against Miami with (a) similar location, both vertically and horizontally, but (b) a large-ish gap in terms of vertical movement.

Below are the life-changing results.

This is a third-inning four-seamer by Hellickson thrown at 90.3 mph and with 2.45 inches of arm-side run and 7.49 inches of rise:

And this is an eighth-inning four-seamer by Peralta thrown at 89.5 mph, with a similar amount of arm-side run (3.46 inches), but about five more inches of vertical movement (12.54 inches total):

Do the differences reveal themselves? They do, I think — although they’re decidedly subtle. Hellickson appears to have a slightly lower arm slot than Peralta, which distorts the perspectives — despite an attempt to control the most relevant variables.

Still, there does seem to be just a bit of an arc on Hellickson’s offering that Peralta’s lacks. In any case — for reference sake, if nothing else — this is what five inches of difference in vertical movement looks like, most other things beings equal.