At the beginning of the Houston Astros' 2019 spring training, Michael Brantley couldn't believe what he was witnessing. Brantley is regarded as one of the purest professional hitters of his generation, a left fielder whose bat control and swing decisions had convinced the team to lavish $16 million a year on him in free agency. That day a 22-year-old left fielder/designated hitter named Yordan Álvarez, who had split the previous season between AA and AAA, was putting on a show in batting practice. After one round of swings, Brantley pulled Álvarez aside.

"I asked him his name, I asked him what position he played and I asked him why they signed me," Brantley said. "I didn't understand."

Even then, before Álvarez stormed into the big leagues in the middle of 2019 and won American League Rookie of the Year, before he made it a habit of looking unstoppable in postseason series, before he established himself as arguably the game's best left-handed hitter and inarguably one of its finest bats period, Brantley knew. It took all of one BP session to recognize what New York Yankees pitchers went into this American League Championship Series understanding: Álvarez is the Astros' answer to Aaron Judge -- a supremely talented leviathan, the sort of player who can carry a team to a championship.

This season, he hit the ball harder on average than everyone but Judge and was the only player in his universe offensively. After winning ALCS MVP honors last season, Álvarez is primed for a repeat against the Yankees, ready to do what he didn't in the last postseason matchup against New York, when he went 1 for 22 in the ALCS as a rookie.

The many feats of Yordan Álvarez that have already become the stuff of legend in Houston would strain credulity if the ubiquity of video and the ball-tracking systems installed in every major league stadium weren't there to verify them -- or if his teammates didn't enjoy telling the stories so much.

Here's second baseman Jose Altuve's entry: In his second major league at-bat, against then-Baltimore starter Dylan Bundy, Álvarez took a second-pitch changeup, low and on the outer half of the plate, and deposited it 413 feet away to the opposite field. On the bench, Astros players stirred. Álvarez had hit 23 home runs in AAA, but this established that he could do more than let his 6-foot-5, 225-pound frame propel balls over the fence.

"We asked him, 'Changeup, to left-center?'" Altuve said. "You normally pull those when you're a rookie. You just pull everything. And he said, 'Yeah, I was looking at some video the night before, and the guy throws change away after a fastball inside.' As a rookie -- that was like, oh, God, that's your first homer, and you're already thinking like that? His approach is so good."

On first base that day stood Trey Mancini, who Baltimore traded to Houston before the deadline this July. After Álvarez rounded the bases on his first homer, Mancini turned to then-Astros first-base coach Don Kelly and said: "Who is this guy?" Kelly's response: "He's gonna be a stud."

"It's just such an easy swing," Mancini said. "It's the same swing every time. He doesn't lose his posture very often. He gets everything he has into it, but it's simple at the same time. It's a beautiful swing. I'm very jealous of it. I would love to have a swing like that."

The Astros were certainly fond of the swing when they pulled off one of the great deadline moves of all-time -- acquiring him from the Los Angeles Dodgers, in a deal for reliever Josh Fields just six weeks after Álvarez signed following his defection from Cuba. But Houston's front office couldn't have imagined Álvarez would be this: 25 years old, with a career line of .296/.384/.590. Even better are his numbers this season: .306/.406/.613 with 37 home runs and 97 RBIs in 135 games alongside a walk rate of 13.9% (seventh in the big leagues) and a strikeout rate that dipped below 20% for the first time this season.

"The most impressive thing about him is it doesn't matter what part of the field," Astros reliever Ryne Stanek said. "Doesn't matter where you go. He has power from pole to pole -- real power. Being as young as he is and as disciplined as he is, is the actually scary part of his game.

"I had never actually faced him until my first spring training here last year. And I faced him my very first live (batting practice) here. It was early in spring. Velo still building. So I was like, all right, well, I know he's obviously really good. I don't wanna throw a bad fastball to him and lose my face. I'll throw him a bunch of splits .... Not realizing that he just absolutely murders changeups.

"Got him on the first one, foul ball. The second one was like, f--- yeah, I'm gonna throw another one. Missile. That's not normal. ... I was like, oh, damn, this guy, he's different."

The Seattle Mariners were the most recent team to leave a series against Álvarez spooked. In Game 1 of their division series against the Astros, he pummeled a Robbie Ray fastball 438 feet for the first come-from-behind, walk-off postseason home run since Joe Carter won the 1993 World Series. On the next day, with Mariners starter Luis Castillo cruising, Álvarez tracked a 99-mph sinker that ran 19 inches -- starting on the inside corner and moving outside the strike zone -- and drove it into Minute Maid Park's left-field Crawford Boxes for another homer.

Following the game, Stanek and Astros closer Ryan Pressly were in the training room watching the replay. Even after seeing Álvarez turn the impossible into reality for years, Pressly was still gobsmacked. How? How, on a pitch at that velocity, with that sort of movement, in that location, could he possibly homer? Stanek's response: "Don't ask questions. Just let it happen."

"Sometimes you get around hitters who the scouting report is just try to get them to hit singles," Astros general manager James Click said. "And I think he's reaching that territory. I remember being on the other side of him in 2019 when we were coming in here with Tampa, trying to figure out how to pitch to him. And you just kind of threw your hands up in the air because there isn't an obvious way to do it. Almost every hitter in the big leagues, there's something -- there's a hole in, there's a hole out, there's a hole up, there's a hole down, there's a hole soft, there's a hole hard, there's a hole lefty, there's a hole righty. And he just doesn't have 'em."

Oakland pitcher Adrián Martinez learned that on Sept. 16. In his first at-bat, Alvarez hit a 95.1-mph sinker 434 feet out to center field. Next time around, Martínez opted for a changeup -- which Álvarez walloped 431 feet out to center again. The third time up, Martínez went back to the fastball.

"And the first pitch, he hits it out to some poor guys trying to have a nice dinner in center field, 460 feet away, never thinking that a baseball was gonna hit them," Click said. "It landed on their table. It was in that center-field restaurant out there. They showed the video of these guys out there, sitting around one of those silver high-top tables and realizing that a baseball was coming for them that had absolutely no business that far away from home plate."

Álvarez came up to the plate once more in the seventh inning.

"The fourth at-bat, he hit a single and everyone was mad," Astros third baseman Alex Bregman said. "And he hit that one 120 [mph]."

It was actually 109.3 mph, but forgive Bregman for the exaggeration. Already that day Álvarez had hit balls at 110.5 in the first inning, 108.7 in the third and 114.9 in the fifth. He does these sorts of things regularly enough that a 120-mph single isn't out of the question (his record this year is 117.4 mph, off Chicago White Sox starter Lucas Giolito on June 17).

Some stories about Álvarez verge on apocryphal. Astros center fielder Jake Meyers said he heard that Álvarez had hit a ball over a net far beyond the outfield fence on a back field at the Astros' spring-training complex. He estimated the distance somewhere between 475 and 500 feet. Bench coach Joe Espada confirmed Álvarez's spring exploits, suggesting he regularly hits batting-practice pitches at least 480 feet. He's gone opposite field into a lake on the property and hit balls all the way out of the complex itself, onto the streets that adjoin the facility.

And if that weren't enough, Bregman said, Álvarez has "great baseball knowledge. Good feel for the game. Good instincts. And he's got all the tools. He can play defense. He can throw. It's accurate, too. I don't know what the numbers and metrics say, but I think this year he's been above-average."

By some metrics, yes, Álvarez was a plus outfielder this year -- a surprise this year, after he had played 174 games at DH compared to 51 in left field entering this season. Particularly impressive is his arm, which FanGraphs' defensive metrics rank third among all major league outfielders in 2022.

Of course, the Astros didn't give Álvarez a six-year, $115 million contract extension in June because of his throwing ability. He's the present and future of the organization because he can hit like few others, because his swing is more holy than holey, because for all the feats Yordan Álvarez has reached in such a short time, there are plenty more to come.

"I just see a professional hitter who has a great understanding of what he wants to do in the box and goes out there and executes on a very high level," Brantley said. "How he carries himself, you would think he has 10-plus years in the big leagues. He has a beautiful swing, and all the physical tools, but at the same time some mental aspects and approach that he carries up to the plate give him a great understanding of what he wants to do.

"It's very impressive how he thinks and how he goes about his business, and it's been an honor to watch him hit."