Pitcher Breakdown - Logan Webb's Fastballs

Logan Webb has long flown under the radar as one the mainstays in the first place San Francisco Giants rotation. At Simple Sabermetrics, we recently highlighted the changes Webb has made over the past few seasons to have his name near the top of the National League pitching statistics categories.


In past articles, we’ve manipulated and visualized Statcast data in R and created a simple Shiny web application. In this article, we are going to briefly revisit the same areas (minus the Shiny application) to break down one of Webb’s most significant changes from last season to this year: the difference in four-seam fastball and sinker usage.


I’ve provided the Statcast dataset and the R script at this Github repository here. If you’d like to acquire Webb’s Statcast data on your own, visit Baseball Savant’s Statcast Search and input the following filters and download the CSV file.




With Webb’s Statcast data from the past three seasons in the fold, we’ll dive right into visualizing the takeaways that Jake made in the video breaking down Webb’s season-by-season metrics.


Pitch Usage by Season


The first visualization we will create is a line plot with the pitch usage percentages for Webb’s arsenal from the past three seasons. As I mentioned previously, the code for each of these plots can be found at the Github repository for this article.



Webb’s four-seam fastball used to be his go-to pitch, but its usage rate this season has dropped it to fourth in his arsenal. He now favors his sinker, which saw a huge jump from the previous season. The frequency of his secondary offerings haven’t changed much from year-to-year, but it’s worth noting that he goes to his changeup or slider nearly half of the time.


One downfall of this plot is that we can’t easily get the exact usage rates per pitch, so we can create a table using the ‘reactable’ package in R to see it numerically. We tossed in bar charts in each cell to still have that hint of visualization within a data table.



Fastball Pitch Locations


Next, we can visualize the location of each four-seam fastball and sinker Webb threw the past two seasons. With these scatterplots, it’s quite easy to see the frequency of each pitch, especially the change of usage from 2020 to 2021.



Although it may be easy to see the frequency difference year-to-year, the density of each area of the zone may be difficult to unravel, so that’s where a heatmap becomes useful.



Neither of Webb’s fastballs were located very well in 2020. His four-seam fastball was thrown in the upper half of the strike zone, which can be a successful strategy for pitchers with higher spin rates, but Webb’s heater is a few hundred RPMs below league average. Specifically, his sinker is nearly 500 RPMs below league average. This pitch was thrown most frequently to the middle third part of the zone, where we may expect it to perform better if it were located lower in the zone because of his unique spin rate.


He hasn’t located the four-seamer much better in 2021, but it has been thrown less frequently, which could be an addition by subtraction, per se. It also doesn’t seem that the sinker’s most frequent locations have moved much, but his ability to consistently throw it for strikes has improved just slightly.


Conclusion


In only his third season in Major League Baseball, Logan Webb has put up top tier numbers to find his name next to the likes of Jacob deGrom, Clayton Kershaw, and Trevor Rogers at the top of the leaderboards. Webb has achieved his success differently than these pitchers, though, throwing with less velocity and at lower spin rates. Nevertheless, he’s utilizing his outlier pitch metrics to induce one of the highest groundball rates and allow the fourth least amount of home runs allowed (min. 80 IP), all while having a wipeout slider with the third highest put-away percentage.

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