The Mystery of Justin Verlander’s Home Runs
In the second half of the season, Justin Verlander has been the best pitcher in baseball. On the heels of a no-hitter over the weekend, Verlander lowered his second-half FIP to a major league-leading 1.91 and his ERA to an AL-leading 1.76, and raised his WAR to 3.2, more than half a win better than second-place Jack Flaherty. On the season, it’s less clear whether Verlander has been the game’s best pitcher. His 2.56 ERA does lead the AL, but his 3.41 FIP is seventh in the league, and even with his 193 innings tops in the game, he’s still nearly a full win behind Lance Lynn in WAR, with Gerrit Cole and Charlie Morton ahead of Verlander’s 5.2 figure as well.
The reason Verlander has performed relatively poorly — even if he’s only the fourth-best pitcher in the AL, he’s having a great season — is due to all of the home runs he has given up. Only Mike Leake and Matthew Boyd have allowed more than the 33 homers offered up by the 36-year-old righty. In some ways, Verlander’s home run troubles are just an extension of the 2018 season. Home runs have gone up from 1.16 per nine innings last year to 1.45 this year; Verlander gave up 1.18 homers per nine innings last year and has given up 1.54 this season. Even if Verlander’s increase was exactly in line with the rest of baseball’s, we’d only be talking about a difference of two home runs, and a 3.28 FIP instead of the 3.41 he currently holds. But that’s still a pretty big difference from his 2.69 ERA, and requires some explanation.
The simple answer behind all of Justin Verlander’s homers is that he’s a fly ball pitcher who throws pitches more prone to homers than most pitchers. A year ago, it might have been that Verlander was a bit unlucky with the long ball. Based on Statcast’s numbers, Verlander’s xwOBA on homers last year was 1.042, which was about 300 points below league average, so he might have had his share of bad luck in that regard. This season, the xwOBA on Verlander homers is 1.317, right in line with the rest of the majors. The same is true when we drop the standards to batted balls with an expected ISO of at least .200. Verlander’s xwOBA on those 97 batted balls was .876 compared to a major league-wide .857, and the resulting wOBA for Verlander was .921 compared to .902 for the rest of the sport. Twenty-five percent of those balls ended up out of the ballpark for the league compared to 31% for Verlander, which isn’t a huge difference. Based on the quality of the contact, Verlander has absolutely earned his home run totals this season. Read the rest of this entry »
Dan Szymborski


