In Milwaukee's sweep of Colorado in the NLDS, Josh Hader faced seven batters -- and retired all seven, with four strikeouts.
This, of course, should come as little surprise. Hader, quite simply, had one of the best -- if not the best -- seasons for a relief pitcher in major-league history.
First, let's recount his statistics from the regular season. In 55 games, Hader had a 6-1 record with 12 saves. In 81 1/3 innings he had a 2.43 ERA, allowed just 36 hits and 30 walks (an 0.811 WHIP) with 143 strikeouts, which is tied for the eighth-most by a reliever in MLB history (with Mike Marshall, who did it in 127 more innings) and the most by a left-handed reliever.
Hader allowed 3.98 hits per nine innings -- that's the best rate of any pitcher in MLB history who pitched at least 70 innings.
| PITCHER | YEAR | IP | H/9 |
| Josh Hader | 2018 | 81.1 | 3.98 |
| Koji Uehera | 2013 | 74.1 | 4.00 |
| Eric Gagne | 2003 | 82.1 | 4.04 |
| Carlos Marmol | 2008 | 87.1 | 4.12 |
| Billy Wagner | 1999 | 74.2 | 4.22 |
If you lower the minimum to 60 innings, Hader places third behind Craig Kimbrel in 2012 (62.2 innings, 3.88 H/9) and Carl Edwards Jr. in 2017 (66.1, 3.93).
Hader's opponent batting average was a minuscule .132 -- the best mark for anyone who had at least 80 innings over the course of a season. He's second when it comes to those with 70+ innings, third with 60+ innings and fifth with 50+ innings.
| PITCHER | YEAR | IP | OBA |
| Aroldis Chapman | 2014 | 54 | .121 |
| Jose Leclerc | 2018 | 57.2 | .126 |
| Craig Kimbrel | 2012 | 62.2 | .126 |
| Koji Uehera | 2013 | 74.1 | .130 |
| Josh Hader | 2018 | 81.1 | .132 |
We mentioned Hader's strikeouts above, but to really put it into context he (once again) had the best per nine-inning rate of anyone in history (15.82). For those with 70+ innings, Hader ranks second.
| PITCHER | YEAR | IP | K/9 |
| Carlos Marmol | 2010 | 77.2 | 15.99 |
| Josh Hader | 2018 | 81.1 | 15.82 |
| Dellin Betances | 2016 | 73 | 15.53 |
| Aroldis Chapman | 2012 | 71.2 | 15.32 |
| Edwin Diaz | 2018 | 73.1 | 15.00 |
Taking it one step further, Hader's strikeout percentage -- the percent of batters he faced who he fanned -- is (stop if you've heard this before) the best in MLB history among those with 70 or more innings.
Even when lowering the limit to 50 innings, Hader still places fourth.
| PITCHER | YEAR | IP | K% |
| Aroldis Chapman | 2014 | 54 | 52.5% |
| Craig Kimbrel | 2012 | 62.2 | 50.2% |
| Craig Kimbrel | 2017 | 69 | 49.6% |
| Josh Hader | 2018 | 81.1 | 46.7% |
| Eric Gagne | 2003 | 82.1 | 44.8% |
Even more impressive, Hader isn't just a one-inning pitcher like many relief stalwarts of the past decade. Hader pitched more than one inning on 33 occasions in the regular season, including 19 times going two or more innings.
He notched seven saves while pitching two or more innings, another rarity (outside of Cincinnati) these days. Since 2000, only the Reds' Rasiel Iglesias has more saves while pitching 2+ innings than Hader; he had eight in 2017.
Hader had seven such saves in 2018. Derek Lowe and Billy Koch also had seven back in 2000. No one else this decade has more than three in a season.
In those seven games, Hader allowed just three hits and two walks (an 0.34 WHIP) in 14 2/3 innings while striking out 28 (17.1 K/9). The only run he allowed came back on April 22 and it was unearned (thanks in part to a passed ball).
Yeah, we think Hader just might be an important piece for the Brewers in the upcoming NLCS against the Los Angeles Dodgers.
Dave Heller is the author of Ken Williams: A Slugger in Ruth's Shadow (a Larry Ritter Book Award nominee), Facing Ted Williams - Players From the Golden Age of Baseball Recall the Greatest Hitter Who Ever Lived and As Good As It Got: The 1944 St. Louis Browns
