
There’s not much for Yankee fans to complain about these days. Despite a plethora of injuries, they have won 12 of their last 13 series and sit in first place in the AL East. The menacing Yankee bullpen has been lights out for the past few weeks, led by Adam Ottavino (1.32 ERA) and Tommy Kahnle (1.57). Third baseman Gio Urshela has stepped into the shoes of an injured Miguel Andujar and has absolutely excelled, carrying the team on his back with timely hitting and good defense (.338/.390/.482, 1.2 WAR). Domingo German has done just as much on the mound, with a solid 3.43 ERA and 3.83 FIP through ten starts. But, in the shadows of the Yankees’ largely successful starting rotation, is a faltering veteran – 36 year old JA Happ.
Happ was the definition of consistency after the Yankees acquired him last July. He allowed three earned runs or less in eight of his 11 starts, pitching to a 2.69 ERA. It seemed like he was only getting better as a pitcher, earning his first All-Star appearance and setting career bests in K% (26.3) and WHIP (1.13).
Then, 2019 happened. It started off with a bang, as he gave up two homers and four earned runs over four innings on March 31. Since then, he certainly hasn’t been able to put it together. After giving up six runs to the Orioles, three to the Royals, and one to the Red Sox, his ERA is up to 4.83, and he’s allowed 15 home runs in 12 starts.
Happ has traditionally been a very fastball-heavy pitcher, relying on his four-seamer for over half his pitches. In 2018, he was among the league leaders in fastball usage, at 59.5%. Still, it was effective – teams batted just .203 against it, with a .301 wOBA and .325 expected wOBA.
So far, however, 2019 has been a completely different story. Batters are crushing Happ’s fastball to the tune of a .657 slugging percentage, a .414 wOBA, and .372 xwOBA. Likely due to these struggles, his fastball usage has decreased to 47.7%.
The collapse of his fastball has forced Happ to throw his secondary pitches more often, but all of them have performed more or less in line with 2018. Happ has used his sinker almost 10% more often than last year, but opponent wOBA has decreased from .318 to just .286. Generally, the same goes for his slider and changeup, which means that the only real difference for Happ this year has been his fastball.
There are a few differences so far this year that help explain why Happ’s fastball has been a problem, and the first and most obvious one is his velocity. His average fastball is down to 91.3 mph in 2019, down almost a full mile per hour from last year’s 92.7. This year marks his slowest average fastball since 2012, when he had a 4.79 ERA for the Astros and Blue Jays.
Next is his fastball command. Fangraphs’ heatmap feature displays Happ’s fastball location in 2018 (left) compared to 2019 (right):

While not a huge difference, it’s clear that in 2018 Happ used his fastball all over the zone, from corner to corner. In 2019, his fastballs have been more confined to the upper part of the zone, where hitters consistently slug over 1.000 against his fastballs. Especially without velocity, an elevated fastball is a dangerous pitch to throw, and Happ is throwing a lot of them.
At the end of the day, Happ’s struggles likely stem from a combination of both fastball location and that dip in velocity. All but one of the 15 homers Happ has allowed have come off his fastball. The average velocity of those 14 fastballs is about 91.4 mph, which is in the bottom 20% among all pitchers.
On the bright side, Happ seems bound to work out his issues at some point. He’s had a few bright spots (7 IP, 0 ER against the Giants; 7 IP, 2 ER against the Angels), and this isn’t even the worst 12-start stretch of his career. In 2015, from June through his first start of August, Happ had a 5.93 ERA in 54.2 innings. After that, he bounced back in a big way with a fantastic August and September, putting up a 1.37 ERA in his final 11 starts of the season.
Happ’s current situation isn’t that much different. Sure, he’s almost 37 now, but there are plenty of metrics that can still keep Yankee fans optimistic that he’ll regain form. For one, his HR/FB rate sits at an unsustainable 19.0%, meaning he’s been somewhat unlucky when it comes to giving up the long ball. He’s also walked just 5.8% of batters, a sign that he isn’t losing his control.
A historically consistent pitcher, we can bet on Happ regain form soon. Friday’s start against the Red Sox was a good step in the right direction – he did allow a solo home run to Rafael Devers, but nothing more. To get back on track, Happ just needs to recapture the mindset he had last year. He should keep on doing what he’s doing when it comes to his offspeed and breaking pitches, but remain careful about the location of his fastball. With diminished velocity, mistakes are dangerous. But, Happ has been through worse, and as good as the rotation has been, the injured Yankees have bigger problems on their hands.
Featured Photo: Paul J. Bereswill, New York Post