What Mitch Haniger could be

In his rookie year, Mitch Haniger suffered through an up and down and up season. He suffered three major injuries, a strained oblique, a bruised finger, and a nasal fracture, which sidelined him for over a third of the season. Through it all, he still managed to capture our attention with a 129 wRC+, including a scorching April where he posted the eighth best offensive line in baseball. Still, as the various projection systems released their verdicts on the upcoming 2018 season, Haniger’s projection stood out as particularly pessimistic. Our memories of that amazing stretch in April and the cold calculations of ZiPS and Steamer stood in opposition. We were left wondering what Mitch Haniger could be.

Haniger’s 2017 season can be easily split into three sections, April, the period in June and July after he returned from his oblique injury, and the stretch of games beginning in mid-August to the end of the season. Below, I’ve compiled a few key stats and split them based on these three periods.

While the Mariners might have insisted that Haniger was healthy when he returned from his first trip to the disabled list, it’s pretty clear that something was amiss. Whether it was rust from sitting out for a month and a half or lingering issues from his injury, his performance took a serious dive in June. In July, he was hit in the hand on a bunt attempt which definitely affected his ability to hit with any authority.

Then he was hit in the face by a fastball and was placed on the disabled list again. When he returned in mid-August, he suddenly started hitting again. He wouldn’t match his outstanding performance in April, but it was still encouraging to see him finish the season on a strong note. The most worrying thing about this stretch was his miniscule walk rate.

While there are many mitigating factors that might explain his mid-season lull, the projection systems take into account all the data without any of the extraneous details. They have no regard for the health of his oblique or the challenges of being a rookie in the big leagues. It’s not as simple as throwing out that data from June and July because we think it’s filled with noise. That’s cheating the system. Instead, understanding how these projection systems work is important in our quest to figure out what Haniger could be.

Modern projection systems are based on thousands of iterations of projections. When taken together, they create the numbers you see listed on a FanGraphs player page. But hidden are the hundreds of variations where the particular player was projected to perform better or worse than the weighted average of the entire sample. Because all projections have this kind of variance built into their outputs, it’s important to understand that the numbers that are informing our expectations for 2018 are not set in stone.

I’ve gathered the output data for Haniger from the three major projection systems in the table below as a baseline for the rest of our discussion.

Of the three projection systems, PECOTA is the most optimistic about Haniger’s upcoming season (it’s also the most optimistic about the Mariners as a team). PECOTA is also the only system that publishes their full range of projections publically. The difference in wOBA between his 90^th percentile projection (.368) and his 10^th percentile projection (.296) is 72 points. That’s a fairly high variance for a batter and it’s likely due to his wild fluctuation in performance last year.

If we go through some of these key stats using the range of projected outputs from PECOTA, we can begin to see how likely it is he’ll match his performance from last year.

BABIP – .299 projected | .065 variance

Throughout his minor league career, Haniger was able to post fairly high BABIPs, especially after he made his swing changes in 2015. But he was definitely the beneficiary of some good batted ball luck last year in the majors. Haniger’s 90^th percentile BABIP is just .329, which is still lower than what he posted in 2017. I think the projection systems are right in calling for a BABIP right around .300.

BB% - 9.1% projected | 2% variance

This is where PECOTA really stands out from the other two projection systems. Haniger posted excellent walk rates in the high minors but saw them fall when making the transition to the majors. Looking back on his season splits, he was able to post healthy walk rates in the first half of the season and only saw a significant decline after his second trip to the disabled list. A 9.1% walk rate seems high because it probably is but a walk rate around 8.5% probably isn’t out of the question.

ISO - .204 projected | .057 variance

Haniger’s power output may be the most important piece of his projection. In April and August/September, he posted almost the exact same isolated power. An ISO of .260 would but him into the same company as Nelson Cruz. That’s probably his peak output. But if he’s able to do that for a few months in 2018, his overall production will probably be much higher than his projected ISO around .200. This is the where I think all three projection systems are selling him short. Even with a depressed BABIP, an ISO around .220 would help Haniger post an offensive line much closer to his 2017 line.