You wouldn’t know it from watching the Yankees last season, but the league-wide home run rate went down in 2018. In fact, the totals dropped to pre-2016 levels. It happened quietly, but the numbers clearly point towards a reversal in the recent home run happy trend.
Many have tried to explain the driving force behind the surge in home runs. The flyball revolution, derived in part from the advent of Statcast measurements like exit velocity and launch angle, goes a long way to shedding light on the phenomenon. Additionally, Ben Lindbergh and Mitchel Lichtman presented a compelling argument that Major League Baseball used a juiced ball to generate offense.
Whatever the reason, the rates have started to normalize. This development proves significant for the Yankees on a number of levels. First, their lineup contains a bevy of sluggers who can send the ball to the moon, whether it’s juiced or not. Aaron Judge and Giancarlo Stanton are just that good. More important, however, is how this stands to benefit the starting pitching staff.
The Yankees have two starters penciled into the 2019 rotation with a propensity to give up the long ball: J.A. Happ and Masahiro Tanaka. Both pitchers have significant home run rates, with Tanaka checking in at 1.44 HR/9 in 2018, and Happ not far behind at 1.37 HR/9. They also have pedestrian HR/FB numbers — 17.7% for Tanaka and 13.4% for Happ. That represents the degree to which flyballs clear the yard. If either pitcher gives up a flyball, it has a decent chance of going for a home run.
Part of this stems from their repertoires. Happ’s modus operandi on the mound is to pound the zone with a steady diet of fastballs. He uses a fourseamer and a sinker to attack hitters. The fourseamer in particular becomes liable to batters turning on it and planting it in the seats. Meanwhile, Tanaka’s signature pitch is an extreme split-finger fastball. If his splitter doesn’t fall out of the zone, it’s an 87 mph pitch over the heart of the plate. That’s called batting practice.
Despite their home run struggles, Happ and Tanaka remain remarkably productive pitchers. Both strike out batters at a rate of around nine men per nine innings. Tanaka also owns a career 47.8% groundball rate. A pitcher who can combine strikeouts with strong groundball numbers makes for one heck of a starter. Their home run blemishes make for just that — marginal weaknesses in their game.
Should the decrease in home run rates continue in 2019, the Yankees have two pitchers who will benefit greatly. Obviously other variables factor into play, like health and their own abilities on the mound. The drop in home run rates, whether from a de-juiced ball or other factors, can’t be ignored though. If all things hold constant, Happ and Tanaka will have an easier time navigating through lineups. The Yankees have an underrated rotation as is, but given this trend, it may be better than one thinks.