New York Mets’ closer Edwin Díaz only closed six games in 2020, but his three blown saves are damn near the only blemish on his stat sheet from the entire season. He posted a sparkling 1.75 ERA (2.18 FIP), 1.25 WHIP and an insane 45.5 percent strikeout rate. That was the highest of his career, and marks the fourth time in five years that he’s posted a mark of at least 39 percent. The bugaboo for Diaz has been that the walks can get him into trouble, and the fact that he can be burned by the long balls in bunches. While he actually got worse in terms of his walk rate, he did improve on the latter.


Despite posting a career worst walk rate at 12.7 percent, he didn’t get burned by the long ball. In 2020, he posted the second-best fly ball rate of his career at 34.1 percent, and minimizing hard contact allowed him to endure a 13.3 HR/FB rate. For the record, in 2019, it was 26.8 percent. After suffering through a 2019 season where he allowed a 16.3 degree launch angle and 43.8 percent fly ball rate, those marks dropped, and his 11.7 degree launch angle allowed is far better.


Keeping the ball out of the air is imperative for Diaz. The two seasons in his career where he posted a ground ball rate under 40 percent, he allowed a HR/9 of 1.36 and 2.33. Yikes. Correlation doesn’t always mean causation, but there’s some pretty strong correlation between Diaz’s GB/FB ratio and HR/9 mark to his ERA.



A big reason for not getting shelled in 2020 is that he didn’t hang out in the middle of the strike zone, for the most part. Take a look at his heat maps for his fastball and slider from 2019 and 2020.


2019 Fastball

2020 Fastball


2019 Slider

2020 Slider


Now, I wouldn’t say his heat maps from 2020 are a work of art by any means, but perhaps a little effective wildness played out well for him. He stayed out of the middle of the zone, for the most part, and the images above likely explain how he posted the worst walk rate of his career.


Since Diaz was able to stay out of the middle of the zone, his slider in particular returned to complete and utter dominance. The average exit velocity against the pitch dropped over nine miles per hour compared to 2020. Furthermore, the whiff rate on the pitch jumped, and the batting average against it was cut in half, and then some.



Sure, his fastball got barrelled up a bit more, but let’s focus on the slider here. His wipeout slider posted a 14.9 percent barrel rate in 2019, but 0 in 2020. Zero point zero.


What Diaz continues to do is strike batters out in punches. He generated a ton of whiffs and did a great job missing bats. His 45.5 percent strikeout was a career best and incredibly impressive. Take a look here at his contact and zone contact rates, as well as his swinging strike rate.


One word comes to mind looking at the above graphic. Phenomenal.


Before we wrap things up, a couple of quick hitters:


  • Only one reliever posted a lower zone contact rate than Diaz

  • Only one reliever posted a lower contact rate overall than Diaz

  • Diaz was one of just two relievers to post a zone swing-and-miss rate above 36 percent.

  • Only two relievers posted a higher swinging strike rate than Diaz.


The New York Mets should be in a position to win some ball games this year, and that bodes well for Diaz. If you’re any sort of superstitious, you might be avoiding Diaz, considering he seems to alternate good and bad seasons. Coming off a good year, his track record shows that 2021 could be full of struggles. However, drafting solely off superstitions typically doesn’t play out well. So, trust the statistics. Now, one of those “bad” years was a 3.27 ERA, and that’s still solid.


He should rack up plenty of saves for the Mets in 2021 with an elite strikeout rate. If you’re a closer early kind of guy, Diaz could be a great target. If you like to wait, you likely won’t be acquiring Diaz’s services. Outside of 2019’s 5.59 ERA, he’s posted an ERA below 3.30 each year, and has two years with a sub-2.00 ERA.

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