One Big Question: Will Heath Hembree ever be able to keep his home run rate down?

Welcome to Over the Monster’s One Big Question series. For those unfamiliar, this is something of a season roster preview where over the next 40(ish) (week)days we’ll be taking a look at each player on the 40-man roster prior to the season. If changes are made to the roster between now and Opening Day, we’ll cover the newly added players. Rather than previewing what to expect in a general sense, the goal of this series is to find one overarching question for each player heading into the coming season. We’ll go one-by-one alphabetically straight down the roster, and today we talk about Heath Hembree.

The Big Question: Can Heath Hembree finally keep the ball in the yard?

Relievers are inherently unpopular among fans due to the nature of the role. Your job is to pitch in big situations and make outs, and it’s rare to be remembered just for doing your job. Players get remembered positively for going above and beyond, and except the truly exceptional — think Mariano Rivera or 2013 Koji Uehara — simply doing your job is generally just going to get a simple head nod. When you don’t do your job in this case, it can very often be the reason your team loses the game, and that sticks with fans. People don’t forget. Moral of the story: If you want to be a major-league reliever, people are almost certainly going to think you’re worse than you are. It’s the nature of the business.

Relatedly, Heath Hembree is a reliever, and he is quite unpopular among Red Sox fans. I’ve defended the righty for most of his career in Boston, and generally I still think he’s probably underrated. That being said, while I’m probably higher on him than most I’ve come down considerably over the last year or so. Hembree has certainly shown flashes and is a useful major-league reliever, but he’s just never been able to take the kind of leap we’ve seen Matt Barnes take in the last couple years. I still believe the tools are him to be a late-inning arm — though probably not up to the level Barnes was at in 2018 — but as he enters his age-30 season the odds are better that he won’t get there. It’s not fair to blame a single issue for holding him back, but if you were making a pie chart of the reasons he’s been held back in his career, the long ball would represent the largest slice.

Photo by Maddie Meyer/Getty Images

First, let’s look at his numbers from last year, because they probably aren’t quite as bad as you remember them being. They’re not great, granted, but they’re....fine. Hembree tossed 60 innings over 67 appearances and in that time he pitched to a 4.20 ERA (94 ERA-), a 4.19 FIP (100 FIP-) and a 3.87 DRA (86.5 DRA-). So, depending on your measure of preference, he was anything from exactly average to slightly better to solidly better-than-average. Obviously that’s not an elite reliever, but it’s also not completely useless.

Before we get to the career-long homer issues, though, the real big difference between 2018 and 2017 (when Hembree was better than he’s given credit for) was his walks. After posting a career-best 6.6 percent walk rate two years ago, he came back last year and posted a 10.4 percent rate, the highest of any year of his career with more than ten innings pitched. I don’t think we’ll see him get back to that 2017 level, but it’s worth noting his plate discipline numbers — everything from zone rate to swing rate on pitches out of the zone to contact rates — indicate he should probably regress back to a league-average-ish walk rate if he pitches similarly. To make it simple and venture a bit of a copout, I’d guess his true-talent is around the midpoint between 2017 and 2018.

Beyond the walks, though, the home runs are more likely to be his undoing in any given year and they are the real reason Hembree has not been able to be more than a solid (at times) middle reliever. Last season in those 60 innings, the righty allowed ten home runs. That comes out to 1.5 per nine innings, his second consecutive year with that rate. Consider that among the 89 relievers with at least 60 innings on the season, only nine allowed homers at a higher rate and Hembree was the only one among that top ten with a walk rate over 3.3 per nine (Hembree’s BB/9 was 4.1). The homers are not a new issue for the veteran. As I said, 2018 was his second consecutive year with a HR/9 of 1.5, and he’s never had a major-league season of at least 11 innings with fewer than a home run per nine innings. For context, this season 29 of the 89 relievers with at least 60 innings allowed one or more homers per nine innings, and the game is only getting more homer-heavy.

One Big Question: Is Matt Barnes really an elite strikeout pitcher?

Photo by Bob Levey/Getty Images

Obviously, when trying to figure out the issues that lead to all of these home runs, his fly ball tendencies play a big role here. Hembree has always been a fly ball pitcher, and while there are advantages to that (particularly with the Red Sox given their outfield defense) it can lead to more costly mistakes. He has been the poster child for that idea. The good news is, according to Fangraphs, the righty has actually been trending up in ground ball rate in every year of his career. In his first season with the Red Sox he got grounders on just 27 percent of balls in play. This past year, that rate was up to 39 percent. The bad news is even that career-high rate is low by league standards. Going back to that group of 89 relievers mentioned above, Hembree had the 28th-lowest ground ball rate.

As with the walk issues we discussed shortly earlier, Hembree’s batted ball numbers may not indicate he should have allowed so many home runs. According to Fangraphs, he wasn’t really allowing all that much hard contact, with both his hard-hit and soft-hit rates in the bottom half of the league. These numbers are not perfect, of course, but they indicate some bad luck. Hembree also allowing a career-high 15.6 percent home-run-to-fly-ball ratio also plays into the idea of bad luck. That said, he hasn’t exactly earned the benefit of the doubt with home run issues in his career.

The bigger issue here beyond bad luck is that he simply fell apart in the second half of the year. His full-season stats can’t be discounted, but they also don’t tell the entire story. Over the first half of the year, Hembree was actually pitching quite well. He had a 3.79 ERA with a 3.51 FIP and a more manageable 1.1 HR/9. Again, not elite, but something you can certainly live with. In the second half, his batted ball numbers cratered. Hembree’s ERA ballooned up to 5.03 in the second half and he allowed 2.3 HR/9. Predictably, his batted ball numbers followed that trend as well. His ground ball rate fell from 42 percent to 35 percent and his hard-hit rate jumped to 52 percent from 23 percent. That last number is staggering, and clearly a big issue.

There’s some inherent small sample size noise here, but he was also just less effective. Looking at his repertoire and zone plots, a couple of things changed. For one thing, he started to move away from his slider and more towards his curveball. At first glance, this wouldn’t have seemed like a terrible idea because his curveball got the most grounders of any pitch by far. However, things aren’t that simple. Hembree’s slider is a lot sharper than his curveball, and hitters weren’t chasing the breaking ball as much. Below you can see a comparison of pitches his opponents were swinging at in each half of the year.

Comparing the two, the difference is clear. Batters had a much easier time laying off balls in the second half, and two zones stand out. The first is above the strike zone with the fastball. I think that comes from the other zone, which is on the right side of the plate. That, of course, is where his slider would be breaking. You see how many batters were chasing that in the first half, and how it wasn’t a weapon in the second. Hitters laying off that pitch leads to more counts in their favor, which takes away the two strike situation to utilize the high fastball. It also, of course, leads to more dingers.

If we’re being honest, the smart money is probably on Hembree not being able to suppress home runs at any significant rate in 2019. He’s just never done it in his career, and at this point at his age it’s smarter to bet with the career trends. And yet, we’ve seen him in flashes look like he can be more, and this is the way to do it. If he can find a way to extend 2018’s first half over a full season with some improved control, that could be the guy we always wanted. Since the Red Sox are seemingly banking on production from unforeseen sources, Hembree at least has the potential to be that kind of jumper. Just don’t get your hopes up too much.