BOSTON — On Jan. 14, 1940, The New York Times published an article under the headline “Sisu: A Word that Explains Finland.”

It was the middle of World War II. The Finns had defended themselves against invasion by the bigger and stronger Soviet Union in the Winter War. A peace treaty would be signed in a matter of months. And a correspondent in Ilomantsi, located near the Russian border, wrote about the national quality that defined the hardy and often inscrutable nation. To understand Finland, you have to understand its favorite word: Sisu.

“Sisu signifies that special kind of strong will,” The Times said. “It surpasses fearlessness and extraordinary endurance. It is a kind of inner fire or superhuman nerve force. It makes an athlete forget fatigue and pain, and risk his life to win.”

Really, The Times published that — even the bit about tired pitchers in the postseason.

In October 2021, Brent Strom, the Houston Astros’ 73-year-old pitching coach, thinks about sisu as his beleaguered staff tries to navigate the playoffs.

“I always refer back to that as a kind of digging deep into your inner soul to kind of get this thing done,” he said while watching his guys stretch on the field at Fenway Park before Game 5 of the American League Championship Series. “I think that's what this bullpen is trying to do.”

Astros scramble to find innings

In the first game of the Astros’ 2021 postseason, their ascendant ace, Lance McCullers Jr., gave them 6 2/3 scoreless innings in an easy win over the Chicago White Sox. An example of Houston’s rotation depth in previous postseasons headlined by Justin Verlander (now recovering from Tommy John surgery), Gerrit Cole (now headlining in New York), or Charlie Morton (pitching for the Braves in the NLCS), or Dallas Keuchel (in Chicago but left off the White Sox postseason roster), or Zack Greinke (available, but limited by aging and late-season injuries), McCullers signed a five-year extension in the spring, posted the second-best ERA in the American League in the regular season, and entered October as his team’s leader on the mound.

Six and two-third innings: a respectable start from a top-line starter, and also the total number of innings Houston got from its starters in the first four games of the ALCS, the fewest through four games in postseason history according to ESPN research. The bullpen covered the other 28 ⅓.

In his second start of the ALDS, McCullers managed just four innings before forearm tightness forced him from the game and kept him off the ALCS roster. Without him — and especially after Luis Garcia exited with right knee soreness in Game 2 — the Astros looked like they would either get dingered to death by the red-hot Boston Red Sox or eventually forfeit from lack of arms.

The bullpen though, drawing on the depths of its collective sisu, kept the Astros’ hopes alive. When Framber Valdez gave up three runs in only 2 ⅔ in Game 1, seven relievers combined to surrender just one more in a tight victory. When Greinke was limited to fewer than 40 pitches in Game 4, five relievers threw 7 2/3 scoreless innings before the Astros’ offense roared back with that seven-run ninth to even the series and shift momentum.

The bullpen’s combined 3.49 ERA while covering the bulk of the first four games represented a heroic effort to paper over a paper-thin pitching staff. Strom said sisu peaks in the postseason.

“They realize what the stakes are and I think what happens is, at this point in time, a lot of the pitchers will take themselves out of their comfort zone, they will they will go beyond what they would normally feel,” Strom said, giving credit to the conditioning coaches and athletic trainers who keep the sore arms coming back for more day after day. That and the sisu: “It’s allowed them to maybe go beyond where they physically or mentally think they should be.”

But even the selfless communal sisu of a bullpen on the brink or a Nordic country can do only so much. The Astros were either going to find a new ace, or face elimination.

“I’ve been blessed as a pitching coach to have Mortons and Verlanders and Coles and Keuchels and those kinds of guys throughout my career, which makes my job a lot easier,” Strom said. “This is a different group. But they’re their own unique group.”

Framber Valdez steps up

“Unique” might’ve been a bit backhanded, but on Wednesday a new one of those guys emerged at exactly the right moment.

It all started, actually, in one of those failed starts from earlier in the series.

“I felt humiliated after that first outing,” Valdez said through a translator about his 2 ⅔ in Game 1. “And I set my mind on not letting that happen again.”

As soon as he was pulled from that game, Valdez made a promise to himself and his teammates for the next start: “Whatever happens, I'm throwing at least seven innings.”

Seven-inning starts are increasingly an endangered species in baseball. Managers rarely let anything other than the most dominant outing stretch to include a third time through the order. Entire games are given over to the bullpen — what’s worse is that it often works. And this postseason has seen the trend toward quick hooks and quirky pitching deployments reach new and at times ridiculous extremes.

Before Wednesday, the longest start this October was 7 ⅔ innings. And then Valdez, facing a Red Sox lineup that’s collectively hitting like Nelson Cruz, threw eight one-run innings — a new career-high for him and more than enough to secure a 9-1 win.

With a one-run lead, Valdez took a no-hitter into the fifth inning, where he promptly gave up a sharply hit single to Rafael Devers and hit J.D. Martinez to put the tying and go-ahead runs aboard.

Manager Dusty Baker decided to go out to the mound to give his guy a break to catch his breath. Valdez saw him coming and was afraid he wouldn’t get the opportunity to make good on his promise.

“Because usually the pitching coach comes out to talk to me first and then Dusty comes in there to take me out of the game,” he said.

He checked the bullpen; no one was warming. The game was still his. Dusty just had some words of encouragement for him.

“'Framboso,' I said,” Baker recalled after the game, “'Man, you're the best. Man, just be natural and just do your thing.'”

On the next batter, Valdez induced a double play.

Sitting in the dugout after the inning, Valdez closed his eyes and cleared his head. He has been working with his psychologist Andy Nuñez in the Dominican Republic on a meditation practice that allows him to stay calm in the pressure cooker of a hostile ballpark in October. It’s a two-step process: first hitting a mental reset button, releasing from his mind anything that happened in the inning prior, and then focusing it forward, visualizing the batters to come and the kind of success he hopes to have against them.

And then he went out and threw another three scoreless innings to put the team on his back, to buy the bullpen an extra day of rest, to send the series back to Houston with the Astros up three games to two.

But it’s not over yet. The whole team will have to dig deep to get this thing done. At this point in the postseason, everyone needs a little sisu.