The unhittable closer anchoring MLB's hottest team

There's an electric right-handed pitcher on an NL contender who is striking out about half the batters he faces with an unhittable fastball-slider combination and who also has a case as the best reliever in baseball right now. His last name is Díaz.

But it's not the one you're familiar with.

Edwin on the Mets, you'll remember, remains sidelined after tearing the patellar tendon in his right knee while celebrating Puerto Rico's win (and his save) against the Dominican Republic during the World Baseball Classic in March. But while the best reliever in baseball last season is expected to miss most, if not all, of this one, it's his unheralded younger brother who could be taking up that mantle.

That's right: Like Edwin, Alexis Díaz is dominating batters with a dynamite two-pitch mix and even has his own signature entrance song (albeit less widely known and celebrated). In 32 appearances, he has allowed only 15 hits while posting a 2.03 ERA, a 0.97 WHIP and a 16.0 K/9 rate. Oh, and he also happens to be closing games for MLB's hottest team, the Reds, who have won 11 straight entering Friday on their way to surprisingly seizing first place in the NL Central.

While everyone (rightfully) has become obsessed with Cincy's rookie sensation Elly De La Cruz, Díaz actually might better represent the Reds -- now making headlines as "America's Team" -- considering both he and his upstart club have come from out of nowhere to have success.

Which raises the first question: Where did Díaz come from?

Edwin, well, he always possessed the pedigree as a Mariners third-round Draft pick in 2012. He peaked as their No. 2 prospect in 2016 by showing impressive stuff and stats in the Minors (3.14 ERA, 1.13 WHIP, 9.5 K/9 in 89 games), initially as a starter before converting to relief in 2016 at Double-A and being promoted to Seattle that season. He registered an MLB-high 57 saves in his breakout 2018 on his way to winning AL Reliever of the Year, just before famously being traded to the Mets along with Robinson Canó for Jarred Kelenic, Jay Bruce, Justin Dunn and more.

But Alexis? By comparison, the now 26-year-old was selected by the Reds out of high school in Puerto Rico in the 12th round in 2015. He missed the entire 2016 season, which would have been his first full pro campaign, with injury. The definition of a late bloomer, he never cracked MLB Pipeline's Top 30 Reds Prospects list, and his Minor League stats (4.03 ERA, 1.32 WHIP in 95 games) did not portend great things, either. All that aside, he slowly progressed his way through the Minors before making the Reds' 2022 Opening Day roster despite never pitching above Double-A.

"He was handling everything in camp," manager David Bell said. "He had a confidence about him. There were a couple of points in camp where we were talking about who was going to make the team and who we were going to send out. I remember a few of us speaking up and said, 'We can talk about anybody, but not Díaz. Díaz needs to stay.'"

And stay he has. Despite starting his pro career in his brother's shadow, Díaz shouldn't be overlooked given how downright dominant he's been to this point. In fact, his rate of 4.1 hits allowed per nine is _the best_ in AL/NL history (minimum 90 innings pitched). He's also working on a streak of 25 straight successful saves, which is the longest active run in the Majors, ahead of -- you guessed it! -- Edwin's 22 in a row.

Which raises the second question: How is Díaz doing, well, what he's doing?

As mentioned above, he's been darn near unhittable, according to both his actual batting average against (.140, fifth best in MLB) and his expected batting average against (.165, seventh best). That goes hand in hand with a 44.0 percent strikeout rate -- second best behind only O's closer Félix Bautista (minimum 30 innings). And although his three most recent outings have been a bit less clean, Díaz still ranks just outside the top 10 in xSLG (at .263) and among the top 30 in both xwOBA (at .259) and xERA (at 2.69).

Díaz does this with only two pitches, too, throwing his four-seamer (52.6 percent) and slider (47.4 percent) almost equally -- similar to his brother's approach. Edwin, however, throws his fastball in the upper 90s and regularly touches triple digits. Alexis, meanwhile, sits more in the mid-90s, which is merely above-average these days. How does he make up the difference? With his 97th-percentile average fastball spin rate of 2,579 rpms, which is among the top 15 in MLB.

Díaz's heater sports a 34.3 percent whiff rate (fifth best in MLB) and generates a putaway percentage -- the rate of two-strike pitches that result in a strikeout -- of 33.3, which cracks the top 10. The slider? That has a whiff rate of 46.2 percent (11th best) and a putaway percentage of 37.9, which is second best.

That's a lot of numbers, so let's just put it simply. Here's what batters are doing against each of Díaz's offerings:

Vs. Fastball: .167 AVG (7-for-42), .214 SLG, .292 wOBA, 19 Ks
Vs. Slider: .123 AVG (8-for-65), .200 SLG, .178 wOBA, 36 Ks

The other differentiator for Díaz? He rocks the very best extension at release point -- a ridiculous 7.7 feet in front of the rubber. That's all the more remarkable given that he's 6-foot-2, which almost makes him "short" compared to some of the towering pitchers surrounding him on this list:

Pitcher (Listed Height): Average Release Extension
Alexis Díaz (6-foot-2): 7.7 feet
Devin Williams (6-foot-2): 7.6 feet
Tyler Glasnow (6-foot-8): 7.5 feet
Jordan Romano (6-foot-5): 7.5 feet
Garrett Whitlock (6-foot-5): 7.5 feet
Logan Gilbert (6-foot-6): 7.5 feet
Bailey Ober (6-foot-9): 7.4 feet

Extension is "definitely important for perceived velocity," as Rays ace Shane McClanahan said in a recent story by colleague David Adler about the topic. That's yet another elite element Díaz brings that makes his stuff play up and so hard to hit even if his fastball velocity -- at 94.7 mph -- is more very good (69th percentile) than great.

With what Díaz and the Reds are doing this season, especially of late, they're fast becoming a hit. Which usually is the opposite outcome batters get when facing baseball's most unhittable closer.

Reds beat reporter Mark Sheldon also contributed to this story.