The beginning of the season has been a struggle for the Yankees, who have won only 5 of their first 13 games. A large part of those struggle is that the players currently on the IL would likely win the AL Central if healthy and surrounded by replacement level players—turns out it’s tough to win games when 5 regulars, your ace starter and ace reliever are simultaneously out. The Yankee bullpen has yet to pick up the slack, with both Chad Green and Zack Britton not performing to expectations.
There is still quite a bit of noise in the data at this point in the season—seriously, it’s been only 13 games even if it feels like it’s been a lifetime—and early-season small sample size has a way of making one look like a fool by the time the weather warms up. But we can still discern trends and identify areas to watch as the season grows older, and that does have real analytic value. Regarding the Yanks bullpen, I am considerably more concerned with Green’s struggles than Britton’s over the long-run, so let’s take a look at what could be going wrong for the Yankees once-fireman.
Since Green fully became a reliever, and a good one in that, in 2017, he has essentially used only two pitches: his four-seam fastball and his slider. The slider is more for show, as it’s not that effective. That’s why he ends up using the four-seamer more than 75% of the time. Last year it was even higher than that, peaking at 93% of the time last June. That’s because his slider isn’t all that effective. He’s hovering at about 75% fastballs so far in 2019, though it’s worth noting he’s re-added his splitter to his arsenal, which Mike covered a few weeks ago. It’s too early to worry about how effective it is—but it’s interesting that Green is trying the splitter again.
Green really needs his fastball to be effective for him to be successful, and while he was still very good last year, there are clear signs that his hitters were adjusting to his fastball. Take a look at this table, comparing his fastball in 2017 and 2018:
Those are still good numbers, sitting comfortably above-average to elite, but that doesn’t mean that there aren’t red flags here, especially for a fastball only pitcher. Hitters started squaring Green up a lot more in 2018, as evidenced above and by an increased HR/9 and reduced K%. It was a lot harder for Green to blow fastballs by MLB hitters in 2018, and that has been so far again this year. That’s probably why he’s trying to fold in more splitters: by introducing that pitch, he hopes to keep hitters off balance and regain that four-seamer’s elite effectiveness.
Existing Red Flags
Relievers are notoriously fickle and unpredictable—that’s why those who are predictable usually tend to be well-paid—and one pitch guys like Green are more susceptible to quick, ugly backslides. (Remember the relievers are fungible days? That was all the rage in the analytic community a few years back.) In fact, there have already been a few existing red flags, even from Green’s dominant 2017. To the data:
Good grief, those 2019 numbers. But leaving those aside, there are interesting data points there in both 2017 and 18, when Green was extremely effective: hard hit % and exit velocity. What those graphs show is that it was really, really hard to make contact against Green but when batters did, they tended to hit the ball fairly hard. His fastball was just so overpowering that it generated a lot of swings and misses, and its spin-rate was so high that it looked even faster than it was.
As Mike has said repeatedly, though, when you only rely on a fastball at the Major League level, batters will eventually start to square you up unless you can keep them honest. That’s why Green dropped off a bit last year. This year, Green hasn’t been able to get the fastball by anyone: he is striking out only 11% of batters compared to about 35% in the last two seasons.
That means more batters are making contact, and, as we’d expect, hitting the ball hard. They’re waiting for the fastball. Hopefully, that’s just a small-sample-size, early-season noise—but as the earlier chart showed, his velocity and spin-rate are trending downward since 2017, in concert with his effectiveness. That trend has continued this year, but I didn’t include 2019 figures because it’s still way too small of a sample to really matter. With that said, however, it should be clear by now how troubling these trends are for a guy with Green’s arsenal.
A Way Forward?
All is not lost, however. Again, it’s extremely early in the year, with the Yankees playing in some cold, rainy conditions recently, including his rough appearance last night. Maybe Green’s velocity increases as the weather warms up and it gives him that extra edge again. That’s just Something To Watch for now, as is his ability to generate swings and misses at the top of the zone.
But what if the velocity doesn’t come back? In that case, it’s going to be extremely important for Green to develop a secondary pitch that is there for more than show. Even in its diminished state, his fastball is an above-average pitch. He can be a very effective reliever and a key part of the Yankee bullpen with it, but that will be considerably easier with a pitch with movement, so keep an eye on that splitter. If batters start biting, that will be a good sign for Green and the Yankees in the long-term.
The problem is that he’s never been able to develop that pitch before in his career, and his MLB success has always been buoyed by his fastball. Given the depleted state of the roster and general ineffectiveness of the bullpen so far in 2019, the Yankees had better hope that’s about to change.