Quick! Without cheating – how many home runs has Edwin Díaz given up this season?

Man, it feels like a million. There was of course that one against Marcell Ozuna to blow the game against the Braves.

And oh, who could forget the demoralizing two-run shot by Aaron Hicks when he blew the game against the hated Yankees. 

And yeah, then there was… Actually, that was it. Two home runs this season. It seems Mets fans have been overly sensitized to Edwin Díaz’s blunders here in his second year in Flushing. And rightfully so – after being acquired in the now-infamous trade with Seattle, he’s been a huge disappointment, exacerbated by the superstar-type development Mets fans have seen from Jarred Kelenic, who was sent to the Mariners in the deal.

You vs. the guy she told you not to worry about.
 
It may seem like a spicy take, but thus far this shortened season, Díaz has been close to the elite reliever New York thought they were trading for in 2019. Below are Statcast peripheral profiles (numbers represent percentile leaguewide), via Baseball Savant, of two relievers. That’s a lot of red – clearly both of these guys are elite.
 
The guy on the left gives up more barrels, but the guy on the right gives up a lot more hard contact. it’s pretty
give and take:
 
You guessed it – there’s a catch. The guy on the right is Edwin Díaz’s 2018 with Seattle. The guy on the left is his 2020 with the New York Mets. It may be inconvenient for the Twitter jokes, and hard to tell through the availability bias involved any time he gives up a game-tying dinger, but Díaz’s improvement this season has been extremely stark. His FIP (fielding-independent measure of ERA), when charted as a moving average for stability, has dropped off a cliff this season, back to 2018 levels:
His strikeout rate has stayed consistent – his best in years:
And perhaps his biggest plague since coming to Flushing, his home run rate, has fallen precipitously since the beginning of the new season, undoing a sad and steady rise throughout a full year in 2019:
Last year, when trying to diagnose just what Díaz’s problem was, I posited that his biggest issue might be his loss in confidence in his slider, his finishing pitch. And yes, throughout last season, he was throwing his deadly slider less and less by the day, at one point throwing it less than 20% of the time. This actually continued a disturbing trend that began in 2018 with the Mariners, but since that doesn’t fit the LOLMets narrative, we don’t need to harp on it.
 
Point is, those numbers have really normalized this year, and his attack has been just as balanced as it was in early-to-mid-2018:
The results have been palpable. I already showed you side-by-side Statcast profiles from these two elite seasons, but things look even more stark with more Fangraphs… well… graphs. Look at how his rolling hard-hit percentage and soft-hit percentage really just shoot apart throughout his disastrous 2019, before almost immediately calming down to 2018 levels this season:

Of course, for many reading this article now, no amount of nerdy graphs and charts can change what the eye test has showed them. He can’t show up in the big moments, he can’t be trusted with the game on the line… some even go as far as saying he should never close a game for the Mets again.

But has he really crumbled in these big moments? Sure, we’ve already seen a couple of examples, but on the whole, the numbers again don’t fit the narrative. The general understanding seems to be that he can’t come in and lock down a tough situation, but Díaz’s LOB% (left on base percentage) of 90.1% is by far the highest of his career, and ranks 3rd in MLB among relievers who have thrown at least as many innings as he has.

The question for the Mets, really, is – what’s the alternative? Díaz leads all qualified Mets relievers this season in WAR, K/9 FIP, and xFIP, and is 2nd in ERA. Sure, his save stats don’t look great – he’s blown 3 saves in 5 chances. But those stats are highly context-driven for a pitcher, almost to the extent of wins and losses, which are finally losing favor among even the non-analytically driven community. After all, last season he successfully saved 26 of 33 chances – would anyone say he had a great year?

Díaz is still just 26, has two more years of cheap arbitration control for the Mets, and is probably their best reliever under contract (especially if Seth Lugo will be a starter for the immediate future). Even if we don’t buy into the idea that Díaz might back to his old self, we should give him credit for the undeniable and significant strides he’s made this year, basically from the opening pitch.