How much did Sticky Stuff Help MLB’s Best Pitchers
Spin rate and grip has become utilized more and more in the game, and its effect on many pitchers in the MLB has been evident in the past few seasons. Having a strong grip on the ball increases the spin rate of a ball, which in turn allows for a less hittable pitch. In the past few seasons, MLB pitchers have began to use foreign substances, including spider tack, which majorly enhance the grip the pitcher has on the ball, and thus increasing their spin rate.
I will examine pitchers Gerrit Cole and Trevor Bauer, both of whom have admitted to using substances.
“Hey Bubba, it’s Gerrit Cole,” “I was wondering if you could help me out with this sticky situation (winky face emoji). We don’t see you until May, but we have some road games in April that are in cold weather places. The stuff I had last year seizes up when it gets cold ...”
“I’ve been chasing spin rate since 2012. For eight years I’ve been trying to figure out how to increase the spin on my fastball because I’d identified it way back then as such a massive advantage. I knew that if I could learn to increase it through training and technique, it would be huge. But eight years later, I haven’t found any other way except using foreign substances.”
Bauer and Cole both experienced a jump of 200-400 RPM on each of their pitches. A jump such as this is extremely rare and in the course of two seasons, is not something that can be achieved naturally barring an incredibly revolutionary mechanical change.
Since there is evidence that both pitchers were in fact using foreign substances to enhance their performance, I will examine what specific effect those substances had.
First, we will examine Gerrit Cole’s increased spin rate and how it has affected his performance and the performance of the batters he has faced.
The graph on the left shows the increase of Gerrit Cole’s spin rate on his fastball per year in terms of percentile, the 100th percentile meaning his fastball’s spin rate is among the elite, cream of the crop pitchers while the lower percentiles signal a more average spin rate compared to the rest of the league. Based on the graph, we can presume that Cole began using substances around 2018. This huge spike in fastball spin is not humanly possible or natural. As a result of these spikes in his fastball’s spin, we also see a spike in his whiff% percentile. Whiffs are essentially when batters swing and miss, in this case against Cole’s fastball. In 2018, which is presumably when Cole began to use substances, there is a major increase in his fastball spin rate. That year, he led the league in strikeouts per nine innings.In 2019, he had one of the best fastball spin rates based on percentile, and as his FB spin rate increased, so did his whiff %. But in 2016 and 17, when his fastball spin rate was at a much lower percentile, he had just an 8.7 strikeout per nine inning rating. Thus it is evident that the increase in his spin rate which was most likely attributed to his foreign substance use had a positive relationship with his increase in strikeouts.
These graphs show the correlation between Gerrit Cole’s three pitches, 4 seam fastball, curveball, and slider, and the expected batting average of the batters he faced. Expected batting average or xBA is a projection of the batting average of a ball hit in play based on the launch angle, and exit velocity of the ball hit, as well as the speed of the batter. So a hard hit ball would have a higher xBA than weak hit balls. As seen in the graphs, spin rate and xBA have a negative correlation when it comes to Gerrit Cole; in that as his spin rate increased for each pitch, the xBA of the batters he faced decreased tremendously from 2017 to 2018.
Credit: Jack Sherbacow
This is a graph of Gerrit Cole’s spin rate and its relationship with the wOBA of the batters he has faced from 2017 to 2021. wOBA is weighted on base average which basically combines all aspects of hitting, including walks, hits, extra base hits and more and factors in which ones are more valuable. In this case, the wOBA on the y axis is the wOBA that batter have when they face Gerrit Cole, and as evidenced by these graphs, a major increase in spin rate also meant a major decrease in batters’ wOBA when they face Cole. The sticky substance that allowed Cole to increase his spin rate evidently allowed the batters he faced from not performing as well in terms of wOBA.
Now we will examine another pitcher who has been known to be a user of foreign substances on the mound, Trevor Bauer. Keep in mind that for Bauer, 2021 data is very limited as he has appeared in just 17 starts and has been on leave for the past month.
These graphs above show the increase of Trevor Bauer’s spin rate over 2017-2021. Similar to Cole, there is a major spike in Bauer’s spin rate, Bauer’s beginning in 2019. Thus, we can infer that 2019 was the start of his substance use and led to a major increase in his overall spin rate.
In the graph on the right, we see that Bauer in 2019 had a average spin rate of 2400 and a Weighted on Base Average of 400 and there was significant increase in 2020, his CY Young year, to 2800 average spin rate and a clear reduction of Weighted on base average to about 250 in regards to his four seam fastball. This much variation is unlikely to be obtained naturally in the span of just a year, so this graph seemingly implies Bauer’s use of substances began in about mid to late 2019. It also shows that the increase spin rate is associated with his effectiveness as a pitcher shown by a major decrease in the wOBA of the batters he faced. A similar relationship is shown in the second part of the graph that illustrates the increase in spin rate and decrease in WOBA for his slider.
The graph on the left examines data from 5 years, 2017-2021 giving us a broader data pool and we can see the same pattern in spin rate and wOBA for the 4 seam fastball.
In the graph on the right, there is a clear trend that as the spin rate increases so does the whiff rate in this 5 year sample. In 2020, where both the spin rate and whiff rate were at its highest for Bauer, he was 3rd in the league in strikeouts per nine innings, and led the league in least hits per nine innings (yes 2021 is much higher, but given Bauer’s temporary leave and the season not yet concluding it is a much too small sample size). In the graph on the left, we are looking at pitches that are very important that the ball breaks at the end; the curveball and cutter. We can see that the relationship between whiff rate and average spin rate. For both pitches he significantly increased his spin rate in 2020 vs. 2019 and was very effective, which shows that there was an unnatural jump in Bauer’s spin rate stats; unnatural jumps that were likely caused by his use in substances, which can allow us to infer that based on both these and Gerrit Cole’s graphs, substances are very effective in increasing a pitcher’s strikeouts.
Our data and graphs analyzes the effectiveness of foreign substances, we can see that they have a relationship with a both a pitcher’s and batter’s performance. Pitchers who go from low spin rates to high spin rates tend to perform better. Gerrit Cole and Trevor Bauer significantly benefited from illegal substances and owe a small portion of their success to the sticky stuff. Of course, Bauer and Cole are exceptionally talented pitchers, and their success should not be discredited due to their use of substances. However, it is evident that there is correlation between an increase in spin rate (one of the most direct effects of substance use) and improved pitcher performance in terms of xBA, wOBA, and Whiff%.
Credit: Jack Sherbacow (Graphs)
