During a recent homestand, Blake Treinen was on his way out of the Oakland Coliseum when he passed by a security guard who addressed him as "Ty." Although the Oakland Athletics closer was confused, he didn't think much of it at the time. A couple of days later, Treinen walked by the same guard.

"Good night, Mr. Young," said the sentry.

For a moment, Treinen was offended by the notion that the guard, someone he had almost daily interaction with, didn't know his name. Then it occurred to him that previously, the guy hadn't called him Ty, but rather Cy.

As in Cy Young.

With all due respect to Oakland's game-day staff, Treinen will most likely not win the American League Cy Young award. Not in a year when Tampa Bay's Blake Snell, he of the sub-two ERA and sub-one WHIP, has reached 20 wins in a breakout campaign. Not in a field that includes Houston's Justin Verlander and Gerrit Cole, both of whom are flirting with the hallowed 300-strikeout mark. Not in a world where Zach Britton had arguably the best relief season ever in 2016 and couldn't crack the top three in the Cy Young balloting. But the fact that Treinen is even being mentioned in the conver-Cy-tion is a testament to just how dominant he has been -- and just how far he has come.

As recently as last year, Treinen was damaged goods, an experiment gone horribly wrong. Following a 2016 campaign in which he excelled in a setup capacity, Treinen -- who was drafted by Oakland in the 23rd round back in 2010 and then traded to Washington in January 2013 -- was one of three hurlers engaged in a heated spring training competition to become the Nationals' closer. It was a role that had long been a sore spot in D.C.

During a 10-year stretch from 2007 through 2016, eight different pitchers led the Nats in saves. One of them was Drew Storen, whose late-inning meltdowns played a key role in Washington losing each of the first two playoff series in franchise history (2012 and 2014). Storen was replaced by Jonathan Papelbon, whose tenure featured him famously choking Bryce Harper in the dugout. Papelbon was replaced by Mark Melancon, whose contract expired at the end of the 2016 season.

Despite the obvious need for an established closer, the Nationals -- who won the National League East in '16 and were expected to do so again in '17 -- whiffed in free agency as Melancon (Giants), Kenley Jansen (Dodgers) and Aroldis Chapman (Yankees) all inked megadeals elsewhere. It was against that backdrop that Treinen stepped into the closer role in Washington, beating out veteran Shawn Kelley and rookie Koda Glover for the gig.

It didn't go well.

Treinen, who entered the 2017 season with one big-league save to his credit, notched his second career save on Opening Day by pitching a clean ninth inning. Two days later, he picked up another save, but allowed a run on two hits in the process. The day after that, he blew a save, and followed that up the next day with a shaky save in which he served up a two-run homer. Less than two weeks later, he was out as the Nationals' closer.

It didn't matter that he'd been lights-out in spring training. It didn't matter that he featured a heavy sinker that reminded folks of Britton and helped him lead all NL relievers in groundball rate the year before. It didn't matter that Treinen's sinker was routinely clocked in the high-90s and even hit triple digits once, a feat so rare it resulted in him being the subject of a clue on the game show "Jeopardy!" None of it mattered. All that mattered was that he wasn't the right guy for the closer job. Not yet, anyway.

"They needed somebody that had done it before," says Treinen, standing in front of his locker before a recent series against the Orioles at Camden Yards. "It's such a high-profile team. The moment you get in there, it's got to be success now because that city wanted a World Series from day one of the season. It's a lot of pressure."

"Dude's nails. Without him, we wouldn't be where we are."

The pressure was so great that, even after being removed from the closer's role, Treinen continued to crack. Pitching almost exclusively in low-leverage situations, he posted an ERA north of five, and opponents hit better than .300 against him. Things got so bad that in mid-July of last season, the Nationals severed ties with the hard-throwing righty, sending him back to Oakland in a trade that brought relievers Sean Doolittle and Ryan Madson to Washington.

The fresh start worked wonders.

Within two weeks of joining the A's, Treinen took over for struggling closer Santiago Casilla. Over the final two months of 2017, he worked to a 2.13 ERA and collected 13 saves, a performance that earned him the full-time closer gig heading into 2018. This season, he has been even better: Through Sept. 23, Treinen led all MLB relievers with a microscopic 0.81 ERA and ranked among the top five in WHIP (0.83, fourth), saves (37, T-fourth), and WAR (3.4, second). As much buzz as Seattle's Edwin Diaz has generated in his quest to break the single-season saves record, Treinen has been every bit as good, and then some. And all it took was a little change of scenery.

"It's just a lot more relaxed for me," says Treinen. "It's the perfect fit for me at this point in my career."

Kelley, the former Nationals reliever who was traded to Oakland in August, has noticed a huge difference. "I see a bulldog who's on the attack," he says of his two-time teammate. "He knows now how good he is. I don't know if he really knew in Washington how good he was. He's the same guy. He's got the same stuff. But now he has the confidence to back it up."

Thanks to that confidence, he has a new weapon.

When Treinen was with Washington, he would often mess around with a cutter while playing catch with Nats starter Tanner Roark. Although Roark encouraged his teammate to bust out the pitch in game situations, the suggestion fell on deaf ears.

"I just didn't want to get beat with it," Treinen says. "That was the mentality that was given to me along the way -- don't get beat with your third or fourth pitch out of the bullpen."

Instead, he relied almost exclusively on his high-90s sinker and high-80s slider, while mixing in an occasional four-seam fastball. This season, liberated by his new surroundings and newfound swagger, Treinen has finally given himself permission to unleash the cutter. A mid-90s offering that starts off resembling a fastball but then darts to the right-hander's glove side, he throws it only about 10 percent of the time. But that's more than enough to keep opposing hitters off-balance.

"He's not predictable anymore," says A's pitching coach Scott Emerson, who has been with the organization since 2003 and knew Treinen from his first go-round in Oakland. "That's made him the complete pitcher."

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Setup man Lou Trivino, who has relied on the cutter ever since he was drafted in 2013, served as a consultant for Treinen earlier this season and marvels at how quickly his fellow reliever has been able to master the pitch. "I've been working on the cutter for five years," Trivino says. "He started working on it for two months, and it's unbelievable."

How good has Treinen's cutter been? Opponents are hitting just .083 against it, the lowest mark in the majors among hurlers who have thrown at least 100 cutters. It has made all his other pitches more effective too: Overall this year, he's limiting the opposition to a .155 average, fourth best among AL relievers and more than 100 points lower than his career clip entering this season. Detractors will point to Oakland's spacious park as an external factor that has no doubt helped Treinen's numbers, but the truth is he has been just as dominant on the road (.406 OPS allowed) as he has been at home (.421 OPS). In other words, everything about Treinen's remarkable transformation is real.

"I've seen what great closers are," says A's catcher Jonathan Lucroy, a nine-year veteran who was the backstop of record when Hall of Famer Trevor Hoffman recorded his 600th save. "Blake has all the ingredients to be that guy. He's got all the tools to be a special player for a long, long time."

As for this season, one of the things that has made Treinen special is how versatile he has been. He has had eight saves of more than one inning, most in the American League and second in the majors behind Cincinnati's Raisel Iglesias. He has entered prior to the ninth inning in nearly a quarter of his outings and entered in tie games more than a dozen times. He even has nine wins to his credit, more than any reliever not named Ryan Yarbrough.

Add it all up, and it's easy to see why Treinen's average leverage index -- a statistic that measures the importance of game situations in which pitchers work, where 1.00 is considered neutral -- stands at 2.24, the highest in the majors. In other words, the guy who couldn't handle the heat in Washington is thriving out west, despite being subjected to more pressure than any pitcher on the planet.

Treinen has been so dominant that, according to ESPN.com's Cy Young Predictor, he's presently ranked second, ahead of luminaries such as Verlander and Cole, and just behind Snell.

"To say that I haven't thought about it, that'd be kind of a lie," Treinen says about the prospect of becoming the first reliever since Eric Gagne in 2003 to win a Cy Young. "But I don't put a lot of stock in it."

What Treinen does put a lot of stock in is being the anchor of an Oakland bullpen that has been one of the best in baseball and a key ingredient in the team's Cinderella success.

After finishing last in the AL West each of the past three years, the A's were expected by many to do so again. Instead, they've already clinched a playoff spot and are on pace to win 98 games, their highest total since 2002. Owners of the best record in the big leagues since early June, they're the wild card that nobody wants to face in October, a time of year when relievers reign supreme. As integral as MVP candidate Matt Chapman and slugger Khris Davis have been to Oakland's roll, the guy at the back end of the bullpen has been pretty instrumental too.

"Dude's nails," Chapman says. "Without him, we wouldn't be where we are."

Perhaps the truest sign of just how much Treinen means to the A's is this: Even though Oakland acquired Mets closer Jeurys Familia in July, then went out in August and got 16-year vet Fernando Rodney, whose 325 saves are second most among active players, Treinen's role remained unchanged. Not that he didn't offer to defer. Shortly after the trades, Treinen approached Emerson and told the pitching coach he'd be more than happy to pitch in the seventh inning. Or the sixth, or the eighth, or wherever the A's needed him. Emerson scoffed at the notion.

Said the coach to his hurler: "We all know you're the closer."

For the first time in his career, so does Treinen.