The Evolution of Scooter Gennett, Power Hitter
One of my favorite baseball games of the decade was played in Cincinnati, Ohio, on June 6th, 2017, between the Cincinnati Reds and the St. Louis Cardinals. That’s the day that Ryan Joseph Gennett hit the 39th, 40th, 41st, and 42nd home runs of his then-five-year-old career, and in so doing became just the 17th player in baseball history to hit four home runs in a single game. Nothing else of any real import happened that night; my delight in its existence is driven entirely by the improbability of Gennett’s accomplishment.
As our own Jay Jaffe noted for Sports Illustrated that week, Gennett was at the time — with the possible exception of Mark Whiten — the most unlikely four-homer player in the long history of the game, and his remarkable power surge appeared then to be one of those strange, miraculous occurrences that baseball occasionally throws at us as further evidence of its unpredictability, like Bartolo Colón throwing 38 consecutive strikes against the Angels, or going deep that one time against the Padres. Nothing, I thought, could be stranger than Scooter Gennett hitting four home runs in one game.
I was wrong. It turns out that hitting for power is kind of Scooter Gennett’s thing these days. In fact, since June 7th, 2017 — the day after his four-homer game — just 27 of the 67 players with as many plate appearances as Gennett’s 635 have a higher isolated slugging percentage than his .220. Since June 7th, 2017, Gennett has a higher ISO than Kris Bryant. Throw in his four-homer day — it did, after all, really happen — and only 16 players top his .239 mark. Gennett’s four-homer game was surprising a year ago. It would be far less surprising now. Scooter Gennett currently has the 10th-highest slugging percentage in baseball (to be fair, his ISO, which strips out the effect of his extremely high BABIP, is significantly lower). One way or another, he should probably be an All-Star. But why? What’s changed?