How Pablo López Transformed His Pitch Arsenal
(4/25/23) By replacing his Cutter with a Sweeper and improving the location of his Fastball, Pablo López has been dominant early in the season.
Originally published on Medium on April 25, 2023.
The Pablo López-Luis Arráez trade between the Minnesota Twins and the Miami Marlins last winter was one of the most talked about transactions from last offseason. Miami received one of the best contact hitters in the game to help bolster their lineup, dealing from their pitching depth and sending to Minnesota a pitcher in Pablo López who the Twins expected to shore up their rotation this season. However, with a few changes to his pitch arsenal, including the addition of a Sweeper, Pablo López has exceeded expectations in his first month with the Twins, and despite Arráez’s hot start to the season, it has become increasingly apparent that Minnesota came out on top of this offseason swap.
Overview:
As shown by the tables above, Pablo López possesses five pitches in his pitch arsenal: a Fastball, Changeup, Sweeper, Sinker, and Curveball. According to FanGraphs Stuff+, López’s Fastball, Sweeper, and Sinker are above league-average, while his Changeup performs really well according to Run Value despite having a lower Stuff+.
In 30.0 innings pitched so far this season, López has been very impressive with a 32.2% strikeout rate and 6.6% walk rate. While this walk rate is slightly below his career average, López’s strikeout rate is nearly 10% above his career average. How has López been able to achieve such great success so far this season? It can be attributed to two reasons: improving the location of his Fastball, and replacing the Cutter he had in his arsenal with a Sweeper.
Change #1: Added Sweeper/Ditched Cutter
The biggest change that Pablo López made to his pitch arsenal this offseason was replacing his Cutter with a brand new Sweeper. As mentioned in a recent FanGraphs interview with David Laurila, López first got the idea of adding the Sweeper from a visit to Driveline in the offseason. “I first got the concept at Driveline in the offseason, but I was only there for a short visit, so I couldn’t really capitalize on the concept of it. Then, in spring training, it was brought up again. From there we sat down and worked on it.”, López explained.
Analyzing López’s pitch movement profiles, it is easy to see why replacing the Cutter with a Sweeper has been successful. First, the addition of the Sweeper improved the movement differentiation between the other pitches in his arsenal. Depending on one’s interpretation, the Cutter was either a slower, less-productive Fastball with cut, or a less-productive Changeup with cut instead of ride. Both descriptions portray a pitch that most pitchers would not want in their arsenal. Second, the addition of the Sweeper improved the velocity differentiation between the other pitches in his arsenal. There is now a considerable amount of difference between the velocity of his Sweeper and the velocity of his Fastball and Changeup, which makes it even more difficult for opposing hitters to be “on time” and produce consistent hard contact.
As shown by Stuff+, the addition of the Sweeper had a major effect in improving the quality of López’s arsenal, by essentially replacing an 82 Stuff+ Cutter with an 119 Stuff+ Sweeper. Minnesota also tinkered with López’s pitch distribution, as he is now throwing the Changeup less, and utilizing his Sinker and Sweeper (relative to his old Cutter) more. In summary, Minnesota tweaked/improved his worst performing pitch (Cutter -> Sweeper), and encouraged López to throw his best pitches more often, enabling him to have an excellent start to the 2023 season.
Change #2: Fastball Location
Another (more low-profile) change that López made to his pitch arsenal in 2023 is that he has been locating his Fastball higher up in the zone, and generating more Whiffs with the pitch as a result.
As shown by the charts above, López typically located his Fastball in 2022 down the middle, towards the outer-half of the plate to RHH, and slightly higher in the zone to LHH. In 2023, his location remained the same horizontally, but he has elevated his Fastball to the top of the strike zone. Without looking at any further data, I would automatically conclude that this would result in more Whiffs and less damage, as middle-middle Fastballs can be a recipe for disaster. Breaking down the results López’s Fastball produces validates these assumptions.
In both 2022 and 2023, López threw his Fastball more frequently to LHH than to RHH. One noticeable change from 2022 to 2023 is that he has been throwing the pitch in the strike zone less frequently, most likely due to locating the pitch higher in the zone, as mentioned earlier. This has resulted in a Chase Rate that is well above league-average, and is higher than what his Fastball generated in 2022. In addition, the Fastball has generated a similarly improved In-Zone Whiff Rate, which I believe can be attributed to improved location and slight increase in Fastball velocity López has experienced this season. Sure, it would be great to see López generate more ground-balls with his Fastball in 2023, however by elevating the pitch higher in the zone, López is making a trade-off of ground-balls for Whiffs, which as evident by his early-season success is an adequate concession.
Concluding Thoughts:
With a few changes to his pitch arsenal, Pablo López has exceeded expectations in his first month with the Twins, and it looks increasingly apparent that Minnesota came out on top of the López-Arráez swap. Replacing his Cutter with a Sweeper has given López another breaking ball to utilize against opposing hitters while also improving the overall Stuff+ of his pitch arsenal, and elevating his Fastball up in the zone has allowed López to generate more Whiffs, thereby increasing his overall Strikeout Rate. With a new four-year, $73.5 million contract extension, Pablo López projects to be a fixture at the top of the Minnesota Twins starting rotation for years to come.
Follow @MLBDailyStats_ on X (Twitter) for more in-depth MLB analysis. Statistics provided by Baseball Savant, FanGraphs, and PitcherList.