One of the bigger disappointments of the 2016 Red Sox season was how human Craig Kimbrel looked closing out games. In particular, he had a lot of trouble coming into tie games where there was no save opportunity. He still had some dominant stretches at times last year but overall his lack of control led to a worrisome 5.1 walks per nine innings. With Kimbrel approaching 29 years old it felt fair to wonder if his best years were behind him.
Kimbrel has been phenomenal in 2017, and as far as I can tell the difference has been the ability to locate his curveball. When he throws that pitch for a strike, combined with his upper 90s fastball, he becomes impossible to hit. Entering Sunday the closer has struck out 13 of the last 16 batters he has faced, which is...pretty ridiculous. In 16 2/3 innings this season he has a 1.08 ERA while striking out 33 and walking just two. His 17.8 K/9 represents the best mark of his career.
One of the more encouraging aspects of Kimbrel's season has been how aggressively manager John Farrell has used him. Thanks to Terry Francona's usage of Andrew Miller in the playoffs last year we know how beneficial it can be to use your best relievers for the most important outs of the game, regardless of what inning that happens to be.
In this past Thursday afternoon's game in Milwaukee the score was tied 1-1 in the bottom of the eighth. With just one out and a runner on Kimbrel was brought in for this high leverage situation. He got out of the inning before Markus Lynn Betts gave the Sox a 4-1 lead with a three run homer in the top of the ninth. Kimbrel got the final three outs in the ninth inning, but with a three run cushion the most important outs of the game came in the eighth with the game tied. Not every situation is going to work out as perfectly as this one did, but it's a good example of how Kimbrel can become even more valuable when used this way.
Entering this season the elite tier of relievers likely belonged to the trio of Aroldis Chapman, Andrew Miller, and Zach Britton. Kenley Jansen has also been great once again and Chris Devenski has thrusted himself into the conversation. But outside of Devenski none of these guys have gotten strikeouts at the rate Kimbrel has this year. That's not a knock on any of them. Kimbrel's ascension to this tier has more to do with how well he has pitched than what his "competitors" have done. Either way he's back to being one of the best relievers in baseball, and he's been the unsung hero of the 2017 Red Sox.