Edwin Diaz's 90 MPH Slider Has Dominant Closer on Path to MLB Saves Record

Danny KnoblerMLB Lead WriterJuly 11, 2018

SEATTLE, WA - JUNE 16:  Edwin Diaz #39 of the Seattle Mariners celebrates after getting the final out of the game to defeat the Boston Red Sox 1-0 during their game at Safeco Field on June 16, 2018 in Seattle, Washington.  (Photo by Abbie Parr/Getty Images)
Abbie Parr/Getty Images

He does most of his work when it's already past midnight on the East Coast, so you're forgiven if you haven't seen Edwin Diaz pitch much this season. It's a good thing we have stats, reports and video to remind us how good the Seattle Mariners' 24-year-old closer has been.

The American League players have noticed, as they gave Diaz the most All-Star votes of any AL reliever, ahead of the better-known (and more often nationally televised) Craig Kimbrel of the Boston Red Sox and Aroldis Chapman of the New York Yankees.

Scouts have noticed how special Diaz has been in what could wind up as a record season for a major league closer, too.

"Swing-and-miss stuff with a wipeout slider," one AL scout said Tuesday.

The Mariners have noticed as well.

"Edwin has been excellent all season," general manager Jerry Dipoto said in a text message. "His consistency, particularly in one-run games, has been one of the biggest contributors to our success in those situations."

Dipoto didn't want to leave out his hitters, whose .266 batting average and .778 OPS in "late and close" situations rank among the best in baseball, according to Baseball Reference.

"Still, Eddy has been a rock throughout," he said.

Diaz had 35 saves in the Mariners' first 91 games, which is the exact same number Francisco Rodriguez had on his way to a MLB-record 62 saves in 2008. No closer has ever had more.

The most common sight in the Mariners' first half: Diaz shaking hands after saving another tight win.
The most common sight in the Mariners' first half: Diaz shaking hands after saving another tight win.Lindsey Wasson/Getty Images

"He's been fantastic," Mariners manager Scott Servais told reporters Sunday after the All-Star team was announced.

You can make the argument that no closer has ever had a better first half. K-Rod had just as many saves, but his ERA through 91 games in 2008 was 2.54. Diaz's was 2.30. Diaz also had 78 strikeouts in only 47 innings, showing off his swing-and-miss stuff and the wipeout slider he sometimes throws as hard as 91 mph.

But the real key, as Dipoto said, has been Diaz's performance in one-run games. The M's entered play Tuesday with 26 one-run wins, the most in the majors, and only 11 one-run losses.

Diaz has saved 20 of those one-run wins, each time coming in with a one-run lead and holding it, which is extraordinary. The major league record for one-run saves in a season is 23, set by K-Rod in his record year.

Overall, the Mariners have handed Diaz a one-run lead 22 times in his 38 save opportunities. His numbers in those 22 games: an 0.81 ERA, with five walks and 40 strikeouts.

Diaz showed off his dominant stuff in the 2017 World Baseball Classic with Puerto Rico.
Diaz showed off his dominant stuff in the 2017 World Baseball Classic with Puerto Rico.Jayne Kamin-Oncea/Getty Images

Even the two times he didn't hold the lead, Diaz allowed only one game-tying run. The Mariners went on to win both games.

None of this is a total shock to those who saw Diaz pitch in the past. While his numbers weren't always spectacular, his stuff was electric. He had the same fastball that can touch 100 mph and the slider that he throws around 40 percent of the time, per FanGraphs.

The Mariners saw the talent when they picked him in the third round of the 2012 draft. The baseball world saw it when Diaz held a stacked Netherlands lineup hitless in the 10th and 11th innings of the 2017 World Baseball Classic semifinal.

He had too many walks (32 in 66 innings) and allowed too many home runs (10) last season, but the slider was nearly untouchable when he threw it over the plate. Hitters were 15-for-104 (.144) with 50 strikeouts against the slider last year, according to Statcast. They're 5-for-76 (.105) with 47 strikeouts so far this season.

"He's always had great stuff and has been good to excellent since coming up in 2016," Dipoto said. "This season, it's been about trust in his fastball, consistency with his slider and overall command (which has been a big step). His personality suits the role, and he's matured before our eyes."

His performance has suited a Mariners team still looking for its first playoff berth since 2001, the longest drought in major North American professional sports. Through Monday, the Mariners had scored only 17 more runs than they'd allowed, and yet they had a 57-34 record that put them firmly in second place in the American League West. They were only three games behind the defending World Series champion Houston Astros and six games ahead of the Oakland A's in the race for the final AL playoff spot.

That isn't all due to Diaz. But without what he's done in the ninth inning, the Mariners wouldn't be anywhere near where they are today.

They now have a chance to get back to the playoffs. And he has a chance to make closer history.


Danny Knobler covers Major League Baseball as a national columnist for Bleacher Report.

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