Are Walker Buehler’s Run Suppression Gains for Real?
Walker Buehler has been on a tear in the second half, leading all pitchers in WAR since the All-Star break at 1.8, just a hair ahead of Adam Wainwright, Frankie Montas, and Max Fried. For the season, he now ranks fourth in WAR among qualified starters (fifth if you include Jacob deGrom’s 92 preposterous innings), toting a 26.9% strikeout rate and a park-adjusted ERA 47% better than league average. His 2.11 ERA is more than half a run better than any other season in his career, and the park adjusted figure is his best by 15 points. It’s another great season from one of the consistently best pitchers in the majors; since becoming a full-time starter for the Dodgers back in 2018, Buehler has posted the 11th-most pitching WAR with the 19th-most innings pitched.
I am not breaking any news by pointing out that Buehler has been and continues to be excellent. The surface-level numbers indicate he has never been better. What caught my eye, however, was how he has gone about doing that. There have been some noticeable changes under the hood. For example, at age 26, he has lost over a full tick of velocity on his fastball compared to any prior season; based on my own research, you would expect a player of his age to lose only about 0.15 mph.
Buehler has also lost almost two percentage points on his strikeout rate. On its face, missing less bats and losing velocity is never something you want to see in a pitcher. (That said, he has brought his ground-ball rate back to pre-2020 levels, going from 35.5% last season to 43.8% this year, similar to his ’19 rate as well as a tick above the rest of the league in 2021.)