Spin Rate has received a lot of buzz lately in the baseball world. It plays a huge role in how pitches move. What do we know as of now? Naturally, gravity pulls a pitch down as it travels towards home plate. The spin rate helps to either defy or help this gravitational pull. 4 seam fastballs have a lot of backspin, which without gravity, would pull the ball upwards. As the ball is cutting through the air, high spin rate fastballs aren’t impacted as much by gravity as much as slow spin rate fastballs. High spin rate fastballs can give the illusion of rising. Low spin rate fastballs are pulled down much faster so they drop, or sink much more. With a curveball, it’s basically the opposite. A curveball has top spin, so the ball will pull downward. A high spin rate curveball aids in this downward pull more than a low spin rate curveball, so in theory, it will have more vertical break. Spin rate alone doesn’t tell the whole story; but generally speaking,you want a curveball to have a high spin rate. Fastballs are a little trickier. Both high and low spin rates can work effectively. You just have to understand your arsenal. High spin rate fastballs tend to produce more fly balls and strikeouts, whereas low spin rate fastballs tend to produce more ground balls. If you have a low spin rate fastball, it might not be in your best interest to pitch up in the zone. If you have a high spin rate fastball, it might be very important for you to pitch up in the zone. For reference, average 4 seam fastball spin rates in Major League Baseball for the 2015 season was 2,226 RPM. Average curveball spin rate was 2,308 RPM.
An interesting discussion surrounding spin rate is what can be done to increase or decrease spin to make the ball move a little more. Earlier this year, things got a little intense on Twitter about substances being used by pitchers in Major League Baseball. It’s been well known that pitchers have used substances for a while, but until recently, there hasn’t been anyway to test just how impactful certain substances are. Naturally, I decided to test out the effects. Using Pitch Tracker from Diamond Kinetics, I have conducted experiments using myself and a few other high school pitchers to see what happens when different substances are used. For the initial experiment, I used sunscreen, spray, baby powder and gum from a Blow Pop. I only threw 4 seam fastballs. Here are the average results:
From the chart, it’s very safe to say that substances will absolutely impact spin. How much is pretty impressive. From a personal standpoint, I would never try using sunscreen by itself. I had no idea where the ball was going with that. What happened with the Blow Pop was absurd. The impact that sort of increase could have for a pitcher is huge. Major League hitters hit, on average, .280 on fastball spin rates between 2,000 and 2,299 RPM. I’m sure this will be fairly linear, meaning that guys probably hit closer to .300 near 2,000 and are probably down closer to .250 around 2,299. I don’t have any stats to back up that claim, but that’s just my guess. Obviously, we aren’t working with MLB average velocity, but this will give you a pretty good idea of what the impact will look like. When fastballs reach 2,600 RPM, hitters hit just.213. If we take average spin (roughly 2,250 RPM to work with an even number) and increase that by just 350 RPM, we are now at 2,600. What do you think would happen if you added another 161 RPM to that? Again, I don’t have the stats for that, but I would feel confident in saying that guys would hit below .200 on average off of that. This could potentially have huge impacts on a pitchers performance.With the success of the gum from the Blow Pop, I decided that I had to test out, not only more brands of gum, but more sticky substances. The next thing I tested out was a Tootsie Roll Pop. I conducted this experiment on myself and 2 high school pitchers. Fastballs are Curveballs for this one:
After conducting the first experiment, I hypothesized that sticky substance’s would increase spin rate across the board. The numbers above destroy that hypothesis with a fastball anyways. If you look at the charts above for fastballs, something different happened for all 3 guys. Player A’s velocity remained the same while spin rate increased significantly. Player B’s velocity dropped some but his spin rate plummeted, which was truly shocking (that also has huge potential implications). Player C saw a jump in velocity without really seeing a notable difference in spin rate. When we look at curveballs, spin rate increased across the board.
So what can we take away from these experiments so far? Not a ton. What is clear is that substances do impact spin.What isn’t clear is how a particular substance will affect an individual’s spin. It appears as though sticky, sugary substances will increase breaking ball spin,but not necessarily fastball spin. Like most everything else, the impacts are going to be different from individual to individual.