HOUSTON – The slow death of the fastball is real. Fifteen years ago, pitchers threw fastballs nearly two out of every three pitches. They grew up in a baseball culture that deified the pitch, as if it were some sacred skeleton key that would unlock success in their other ones. Today, pitchers throw fastballs less than 56 percent of the time. A full quarter of pitchers live off cutters, sliders, curveballs, changeups and use the fastball as a secondary offering – almost an on-speed pitch. Of baseball’s manifold recent evolutions, this one affects the game more than any, because it’s the great impetus behind the surge in strikeouts.

It was peculiar, then, to see a left-handed pitcher flinging 90-mph sinkers – relics of a bygone era – to immense success in Game 1 of the American League Championship Series. Dallas Keuchel, of course, is something of a throwback, a groundball machine in a flyball society, a sinkerball pitcher in a bent-ball game. He throws a slider and a cutter and a changeup, too, and he’s not pumping his two-seam fastball like it’s his bread, butter, steak, potato and asparagus. In this moment, though, this odd epoch of baseball, where the game is trying to understand what it wants to be, Keuchel is unique, for if the fastball is bleeding out, he’ll gladly leave behind a trail of crimson on his way to victory.

Keuchel’s sinker emasculated the New York Yankees on Friday night. The Houston Astros rode the pitch to a 2-1 victory to take a one-game-to-none lead in the ALCS, just as they’d ridden it in Keuchel’s previous seven outings against New York. To say Keuchel owns the Yankees does not do justice their struggles against him. This is straight pwnage, the kind personified in Game 1 by seven innings of four-hit, 10-strikeout, shutout baseball.

“There’s really no hard explanation for it,” Keuchel said afterward, and if that does not do his sinker justice, that is all well and good. It is not a flashy pitch. His index finger resides along the seam just below the ball’s Rawlings imprint. His middle finger covers the white hide next to it. His thumb crosses the seams on the bottom. And that’s about it.

Well, not quite it. Something about the fashion in which Keuchel delivers the pitch turns the two-seam fastball into an instrument of destruction. This season, 66 pitchers threw at least 500 sinkers. At 89.15 mph, Keuchel’s was the fourth slowest. And still, he generated swings and misses on nearly one-fifth of them. And his 11.07-to-1 groundball-to-flyball ratio on sinkers put into play was far and away the highest in the major leagues. As was his 76 percent groundball rate. And his 7 percent flyball rate. And his 17 percent line-drive rate.

Someday, as pitch-tracking technology improves, quantifying what makes a great sinker great may be easier. Nothing in the mound-to-plate movement of Keuchel’s makes it particularly unique. Every hitter talks about it in reverential terms, as though its late movement embodies some sort of mystical quality that can be summed up one word at a time.

“Gross,” Alex Bregman said.

“Nasty,” George Springer said.

“Filthy,” Brian McCann said.

“Baffling,” Josh Reddick said.

“Pinpoint,” Luke Gregerson said.

“Perfect,” Carlos Correa said. “It’s just the perfect pitch.”

Those are six of his Astros teammates, five of whom played in Game 1 and one of whom marvels from afar in the bullpen. And each saw the Yankees try and fail to square up a pitch that travels at speeds rarely seen from fastballs. While it’s true two-seam fastballs tend to move slightly slower than their four-seam brothers, it’s also true that in those 15 years that the fastball rate has dipped, its average velocity has risen in staggering fashion. This year’s average fastball clocked in at 92.8 mph, according to Statcast – and even higher if measured at a further distance, as Brooks Baseball does. The average fastball in 2002: 89 mph.

Teams today also understand the easiest pitch to hit is a fastball, so they’ve adjusted accordingly. This year, more than 720,000 pitches were thrown. Around 400,000 were fastballs. In 2002, there were about 699,000 pitches, 450,000 of which were fastballs. That’s 20 fewer fastballs per game in 2017. The Yankees’ Game 1 starter, Masahiro Tanaka, exemplifies the trend. Fastballs accounted for only 27.6 percent of the pitches he threw during the regular season. The entire Yankees staff threw fastballs just 44.9 percent of the time.

Of Keuchel’s 109 pitches in Game 1, 56 were fastballs. The Yankees looked at half of them for strikes. They put seven in play: four on the ground, a pair for singles and just one lofted in the air. Half of his strikeouts came on the sinker and the other half from his slider, a putaway pitch that allowed Keuchel to reach double-digit punchouts for the first time since September 2015.

He again looked like the April-and-May version of himself during which he was one of the five best pitchers in the game. Then came a neck injury that sidelined Keuchel for nearly two months, a rough-and-tumble return in which consistency evaded him and a September straightening-out in which flashes of his best self showed up often enough to hearten the Astros.

“I never doubted that Dallas was going to be able to get right and get back,” manager A.J. Hinch said. “But there was a gap in the season where when you lose one of your best pitchers, there’s always cause for concern. He’s the anchor of what we’re doing. He really sets the tone for the entire pitching staff, and to lose him during the season, I was more concerned about that. I knew Dallas would find a way to get himself right and get himself ready.”

This was more than ready. The gross, nasty, filthy version of the sinker revealed itself as Keuchel struck out four batters in the first two innings. The Yankees, coming off a stunning triumph over Cleveland in the division series, were indeed baffled. With just one walk against the second of the 26 batters he faced, his control was pinpoint and his command of the pitch perfect.

“You tell him to throw a ball here 10 times, he’s going to do it 10 times in a row,” said McCann, his catcher. “He doesn’t miss.”

Because of that, Hinch felt comfortable when Correa and Yuli Gurriel drove in runs in the fourth inning to stake the Astros a 2-0 lead. Keuchel needed help from a tremendous Marwin Gonzalez throw that cut down Greg Bird at the plate in the fifth inning, and the Astros needed to take a deep breath when Bird halved their lead with two outs in the ninth inning by banging a home run off the right-field foul pole. Closer Ken Giles hung on for a five-out save and staked the Astros a one-game advantage with Keuchel’s co-ace, Justin Verlander, ready to oppose Luis Severino in Game 2 Saturday.

Friday was Keuchel’s alone, and he delighted in the moment. Only 23 pitchers in 2002 with at least 20 innings threw fastballs fewer than 50 percent of the time. This year, there were 133. Nearly 58 percent of Keuchel’s pitches this year were fastballs, the highest mark in his career, and he’s proof that one need not throw hard nor disown the fastball in order to succeed. Even a humble sinker can beat the Yankees.

“It’s just a storied franchise and they have so much rich history that you almost don’t even have to get up for the game. You’re already up for it,” Keuchel said. “That’s what they bring. They have a lot of talented players, and this was supposed to be the bridge year for them, and they weren’t supposed to be here, but they are because they are good, and they are the Yankees.”

Yeah, well, he is Dallas Keuchel, 2015 Cy Young winner, sinkerball extraordinaire, maestro of ALCS Game 1, in which the fastball felt alive as ever.