Will the real Ian Happ please stand up?

On May 2 Ian Happ was 3-for-5 with a double and a home run when a scary outfield collision with Nico Hoerner resulted in him being carted off the field. He was subsequently placed on the injured list and while it looked like he might be reactivated for Friday’s game against the Cubs game against the Tigers, Tim Stebbins reported yesterday that Happ’s recovery is taking a bit longer than expected.

I find myself wondering which version of Happ the Cubs are going to get when he comes back, because I had a lot of hopes in the early innings of that game in Cincinnati that he had finally fixed whatever was contributing to a pretty remarkable slump. Let’s use today’s off day to try and figure out what is behind Happ’s .167/.307/.250 slashline.

The first thing I looked at was Happ’s career wOBA compared to the league average. For those of you less familiar with advanced metrics, wOBA is just a fancy type of On Base Percentage that gives you more credit if you get on base with a triple than if you get on base with a single. So here’s a look at Happ’s start to 2021:

FanGraphs

Those numbers are bad. They are worse than Happ’s struggles in 2018 that resulted in him spending the vast majority of 2019 at Triple-A Iowa. But the season by season look at wOBA doesn’t tell us as much as some other looks at the stat can. One of the fun things you can do with stats on FanGraphs is look at rolling averages by a certain game period which allows you to see hot stretches and slumps. It also allows you to see those trends across the arbitrary start or end of a season. So next up is Happ’s 20-game rolling wOBA since 2017

FanGraphs

This look gives us a sense of Happ’s (admittedly early) career peaks and valleys. As you can see, he’s had a number of hot streaks, but his slumps have actually gotten more pronounced. A lot of us really loved what we saw from Happ in 2020. He very much looked like a dark horse MVP candidate for the first month of the pandemic shortened season. He has not looked like that for the first month of 2021. There are two potentially worrisome trends from Happ so I wanted to look at each overlaid on his wOBA to see which line up the best. The first is K percent.

Close watchers of statistics and the Cubs will remember that Ian Happ’s K percent spiked in 2018. He finished the season striking out an eye popping 36.1 percent of the time. He managed to lower that in 2019 and 2020 to a still high, but more manageable, 25.0 and 27.3 percent, respectively. In 2021 that number is back up to 32.4 percent.

FanGraphs

While it is obvious that Happ’s lowest strikeout periods correspond to his best stretches by wOBA, it’s also true that there are times, as happened at the end of 2018, where both are spiking. So it seems like Happ does strike out more when he’s struggling but it also doesn’t look like it’s the main cause of Happ’s offensive woes.

The second thing I was really interested in was Happ’s ground ball percent, which is at a career high 54.9 percent. So let’s start with the graph:

FanGraphs

Now we are on to something. Both of Happ’s most pronounced slumps in his career have been the result of his most extreme ground ball rates. To me the increased ground ball rate is actually a better indicator of Happ’s problems than his K rate is. There have been times in Happ’s career where he’s swung and missed a lot but still been very productive when he’s made contact. Where Happ struggles is when he’s searching for contact and driving the ball into the ground as a result. You can see this in the collapse of Happ’s launch angle, which has collapsed in 2021 to 3.3 degrees as opposed to a career norm of 11.9 degrees.

Happ is still a young player, it’s easy to forget that he’s just 26 years old. I have a lot of faith in Happ to rebound during 2021 but in order to do that he needs to go back to hitting the ball in the air instead of driving it into the ground more than half of the time he makes contact.