Milwaukee southpaw Josh Hader continues to be one of the most electric relievers in the game. From an overpowering fastball, to a wipeout slider and long-flowing hair, Hader has been one of the game’s best late-inning men. Since the start of 2018, Hader has posted the seventh-most saves (62), a top 20 ERA at 2.66 and a league leading 46.4-percent strikeout rate. Think about it this way: Hader has struck out almost half of the batters he has faced since the start of 2018.

Since the start of 2018, only Seth Lugo has a higher wFB than Hader (32.9), and only nie relievers have a higher wSL than Hader (16.0). While his repertoire does produce a lot of strikeouts, the usage of his fastball is prone to fly balls.

His fastball lives in the upper-third of the zone, and understandably so, it has resulted in a launch angle of 20 degrees or higher in four straight seasons, culminating in 2019 and 2020 rates at 29 degrees and 28 degrees respectively. Fortunately, the exit velocity on his fastball dropped in 2020 (89.8 mph) from his 2019 mark (91.3), and limiting the amount of hard contact on his fastball is key for Hader. Because of this, home runs have been a problem for Hader. The southpaw was one of 4 qualified relievers to have a fly ball rate above 58 percent in 2020.

Inducing ground balls isn’t exactly at the top of Hader’s priority. With an overpowering fastball, he can afford to leave it up in the zone more often than not. However, he’s now posted three straight seasons of a sub-30 percent ground ball rate. The only thing with Hader is that his current repertoire doesn’t really allow him to be a ground ball aficionado. His fastball doesn’t really allow opposing batters to get on top of it, and his slider induces more whiffs than anything. In 2020, his slider generated a 51-percent whiff rate and a measly 74.9 average exit velocity against.

Now, the big thing from Hader’s 2020 is his massive jump in walk rate. In 2020, it was 12.8-percent, well above the 9.8-percent and 6.9-percent from the two seasons prior. However, that number is a bit flawed, due to one bad outing. In late August, the Pittsburgh Pirates of all teams, drew five walks against Hader, and he recorded just one out. If you remove that outing, his walk rate is down to 6.9-percent for the year, and matches his 2019 rate. So, yes, up front, it doesn’t look good, and it shows that Hader has that propensity to lose all control of the strike zone, but he’s not a 12-percent walk guy. He’s not completely off the hook, however, as his 39.2-percent zone rate was the lowest of his career by a significant margin.

Could this be a result of his shift in repertoire?

You can see that he used fastball less than ever before in 2020, while using his slider more than ever before. The great thing with the increased usage of his slider is that it didn’t skip a beat in terms of generating whiffs, and it’s a lethal weapon that he has in his back pocket. Now, using the fastball less is interesting, and he was also out of the zone with the heater more than ever before in 2020. Will his usage in 2021 be more comparable to 2019 or 2020? I would probably say somewhere in the middle of those two campaigns.

Hader is currently going as the first reliever off the board in NFBC drafts, just a few spots ahead of Liam Hendriks . Devin Williams is in the fold in the back end of the Milwaukee pen, but barring a trade, the ninth-inning is Hader’s and that isn’t going to change. Honestly, 2021 is likely a lot of the same for Hader, where he’ll continue to post elite per-inning metrics, but he’s going to allow plenty of fly balls when he doesn’t send batters walking back to the bench after punching out.

At some point during the year, if he does get traded, his value could take a hit, but he’ll still provide elite ratios and be a massive source of strikeouts. Losing some saves would hurt his value overall, unless your league values holds as well, then in that instance, he will remain elite.

Statistical Credits:
Fangraphs.com
Baseballsavant.mlb.com
nfc.shgn.com/adp/baseball