Who is Josh Hader?

Brewers left hander Josh Hader is causing quite a stir thanks to his strike out mania. The Milwaukee reliever began the season with a fascinating 15.3 IP performance in 10 appearances, striking out 31 of 53 batters faced. But the breakout arguably occurred on April 30, 2018, when Hader completed an eight out save (2.7 IP) by striking out eight batters at Cincinnati; only one walk kept it from “perfect outing” status. Since that performance, Hader experienced his first blown save of the year, but was picked up by his teammates for the win, and progressed to another absurd strike out performance in Minneapolis: Hader struck out six batters across 2.3 IP against the Twins to pick up the win in Saturday night’s close contest.

For a team that is seriously out performing their run differential (expected Runs Scored / Runs Allowed record), Hader more than any other pitcher personifies a bullpen that is ready to support their club in any scenario and (usually) bring home the win. Even failings in close games, such as Sunday’s 1-3 loss to the Twins, typically have the stamp of a poor offensive performance, leaving it difficult to fully blame the bullpen or pitching staff as a whole unit. Hader is also quite a thrilling personality, as he exemplifies one of the prospects acquired during the first rebuilding stint (started July 2015 by President Doug Melvin) reaching the MLB in a successful role. Now that Hader is a successful reliever, it’s tough for fans to remember that not even three years ago he was a questionable prospect that could offer many potential futures to the Brewers; now Hader represents a winning club on the field, which undoubtedly enhances his face of the post-rebuilding Brewers.

It’s tough to hang on a role on Hader right now. The southpaw is undoubtedly capable of serving as a closer, as well as a multi-inning fireman in any part of the game. He’s a true strategic role player for the Brewers, but even his elite performance is not enough for some fans; some Brewers fans and analysts continue to question whether Milwaukee should employ Hader as a starter, insinuating that even 27.3 IP, 1.10 DRA, 8 runs prevented (!) of relief work are not enough to settle the question of Hader’s role.

Yet, evidence is emerging that Hader himself is part of a vanguard of multi-inning relievers working in the game. Much of the credit for this trend goes to Andrew Miller, who assembled a thrilling set of multi-inning performances during Cleveland’s 2016 march to an American League Championship. But Miller is hardly the face of this high inning relief movement; in fact, when searching for MLB relievers that work at least 1.50 IP/G and work exclusively during relief (Relief IP / Overall IP = 100%), Andrew Miller is nowhere to be found. What is found, however, is that Josh Hader is one of nine long multi-inning relievers working in 2018; for context, the season is hardly a quarter of the way through, and nearly as many long multi-inning relievers are working in 2018 as worked during 2016-2017 (11. See Table One below).

Table One: Long Multi-Inning Relievers, 2013-present (Minimum 1.50 IP / G, 100% Relief IP)

What is striking about this trend is that while the long multi-inning relievers employed in 2013 were mostly quality pitchers judged by Deserved Run Average (DRA), from 2014-2017 the arms were mostly unsavory options, which leads one to wonder whether these relievers were closer to the standard “long mop up option” than 2018 Josh Hader. Now, in 2018, Josh Hader is one of several quality long relievers working.

Table Two: Classic Strike Out Relievers, 1962-1994 (Minimum 75% Relief IP, No IP/G Minimum)

Hader’s absurd strike out performance is also worth noting in terms of redefining this long multi-inning reliever role. Hader’s strike out performance can easily be assessed against classic closers, and while his strike outs are exciting, adjusted for era one can find that there are a classic group of MLB relievers and swingmen who ably exceeded the strike out averages of their respective leagues (Table Two, above). 30 years ago, strike out rates were approximately 35 percent lower than current totals, which means that strike out statistics must be normalized or indexed to the league environment in order to compare performances across eras. Using Baseball Reference League Encyclopedia and Baseball Prospectus historical Individual Pitching Stats by Team, I contextualized strike out performance by indexing a pitcher’s individual strike out percentage (K%) to their league’s percentage. By assessing the “K_Index” alongside innings pitcher per game, one can get closer to normalizing relief performance across time and assessing relief pitching excellence. Thus, although we will see below that Hader’s strike out performance is very good, there is a group of historical arms, especially Rob Dibble, Ron Davis, Bill Caudill, Duane Ward, Lee Smith, and Norm Charlton, who compare quite well to Hader while also working significantly more innings (it will be interesting to see if Hader maintains his early strike out brilliance for a 70-to-90 IP workload).

In terms of assessing workload, the Brewers’ young southpaw has yet to reach the 2.0 inning per game threshold, but there is a “classic bullpen era” (1962-1994) set of pitchers that may serve as an aspirational model for designing Hader’s role moving forward. Table Three (below) lists forgotten relievers that worked from 1962-1994 with at least 2.0 IP per game, sorted by strike out excellence.

Table Three: Classic High Strike Out, High Inning Relievers, 1962-1994 (Minimum 2.0 IP / G, 100% relief IP)

Note that while many of these relievers would not fit “our” current understanding of a closer or high leverage reliever, this group of relievers generally were strike out monsters of their time, compiling relatively high strike out rates during comparably low strike out eras. The DRA follow suit, as 26 of these pitchers posted DRA below 3.50.

Table Four: Modern High Strike Out Relievers, 1995-Present (100% Relief IP)

Assessing “modern” relievers after the beginning of the Wild Card era, it is difficult to find a solid relief role comparison for Hader. Yet, the fun of the southpaw’s strike out performance is that he is an elite pitcher whether one compares his performance with short inning closers or high inning relievers. For example, Table Four (above) demonstrates that Hader’s overall strike out index is better than any modern reliever save for Eric Gagne, and the adjacent presence of Billy Wagner and Aroldis Chapman provide tantalizing southpaw comparisons. Table Four is truly a list of “who’s who” closers over the last 24 seasons, coupled with a few other surprises.

However, part of Hader’s appeal in his current role is that manager Craig Counsell can employ the lefty for six or more outs during a single appearance. This seemingly places Hader in special company within the modern game; after all, only Rafael Soriano, Joba Chamberlain, Francisco Rodriguez, and Troy Percival come close to reaching Hader’s IP / G in Table Four. Thus, it is also worth comparing Hader’s exceptional performance to relievers with similar innings pitched roles. Table Five (below) demonstrates another terrain of the modern game that helps to define Hader’s current value as a reliever.

Table Five: Modern High Innings Workload Relievers Ranked by Strike Out Performance, 1995-Present (Minimum 1.50 IP/G, 100% Relief IP)

Once again, Hader shines: whereas the southpaw demonstrated an extremely high workload among the modern closers in Table Four, in Table Five his strike out rate shines among modern pitchers that worked longer outings. Here, more thrilling left handed comparisons emerge, specifically Norm Charlton and Arthur Rhodes. I also expanded Table Five beyond 30 pitchers to showcase Tyler Glasnow, who is another 2018 high inning reliever posting a very strong strike out rate. While Glasnow’s surface statistics do not appear as great as Hader’s thus far, there are peripheral aspects of the righty’s performance that suggest that he could improve. Together, Hader and Glasnow suggest that there may indeed be a sea change in how managers are viewing relief roles (and, perhaps, how front offices are viewing testy starting pitching prospects with delivery and command concerns). The crucial difference between Glasnow and Hader, of course, is that Hader did not need to fail as a starter prior to moving to the bullpen, and it is worth questioning whether that type of player development decision is crucial to Hader’s success as a reliever thus far.

In 2018, Brewers fans are witnessing an elite bullpen, with Hader undoubtedly serving as the sparkplug and the most exciting graduate out of the farm system. The southpaw served as the sparkplug by covering high leverage situations during closer Corey Knebel’s absence, ostensibly giving Counsell more freedom to be more fluid with bullpen roles after Knebel’s return. Hader is arguably the most exciting graduate out of the farm system not only due to his excellent performance during a playoff run in 2017, but due to his enhancement of that role in 2018. With the caveat that much can change over the course of the season, Hader thus far has rightfully sparked excitement by producing a relief performance that has rarely been seen either from elite closers (in terms of innings workload) or high workload relievers (in terms of strike outs). So where will the “regression” take Hader throughout 2018? Hopefully these tables provide numerous comparisons for the lefty, as well as key role comparisons for how MLB managers can use their arms: there is an entire generation of high workload relievers that are forgotten, falling outside of the praise of the classical closers yet giving hints for how a new generation of arms can be employed. Hader and a group of other 2018 hurlers could serve as the vanguard.

Photo Credit: David Kohl, USA Today Sports Images

References:

Baseball Prospectus. Individual Stats – By Team. CSV retrieved May 20, 2018.

Baseball Reference. League Encyclopedia. CSV retrieved May 20, 2018.