Yes, really. With a loaded stat line and 14 saves more than the next reliever on the list, Mariners reliever Edwin Diaz was the best closer of the 2018 season (sorry, Treinen). But let’s take it beyond the best closer: he was the best pitcher.
The Cy Young has historically been a starter’s award. Plain and simple. And while this article is not meant to knock some of the best in the business, the dominance of Edwin Diaz for the Mariners earns him consideration among the top.
It’s impossible to deny that the American League was loaded with pitching this season. Chris Sale was the ace behind the American League-winning Red Sox. Blake Snell is the odds-on favorite to win because of his breakout dominance in 2018; he allowed just a .178 BAA while striking out 221 en route to a 21-5 record.
Forget the odds. I’ll get to his stat line shortly, but Diaz had an x-factor that would terrorize opponents and energize fans. Everyone knew the game was over when he took the mound. In fact, the Mariners never lost a game when Diaz entered a game with a lead of one. His 27 one-run saves in 2018 shattered Francisco Rodriguez’s all-time record of 23.
And while we cannot determine the best closer merely by saves (57 for Diaz, by the way), hitters were unable to solve Edwin’s pitching. Despite having a smaller sample size than starters, Diaz outperformed aces on multiple stat lines. His 0.79 WHIP trounces Justin Verlander’s AL-best among starters (0.90). In 73.1 innings, Diaz struck out 124.
To put this into perspective, 56% of his outs were via strikeout. His 15.2 strikeouts per 9 innings were nearly 3 more than the best starter in all of Major League Baseball (Gerrit Cole, 12.39 SO/9).
His ERA of 1.96 was not the best among relievers, but his inconsistency during non-save situations is to blame. Half of his earned runs were accumulated in the 16% of his appearances that did not warrant a save opportunity. However, this lousy statistic showcases his brilliance as a closer when a save was on the line: He allowed just 8 runs in 61 save situations.
After having the best season by a closer in Mariners history (and one of the best seasons ever by a reliever), it would be unfair to exclude Edwin Diaz from the conversation for the American League Cy Young Award. Is he a long shot versus the aces of the world in Sale and Snell? Sure. But his dominance in the clutch justifies his consideration among top-tier pitchers.