BOSTON -- There are many reasons the Red Sox have vaulted themselves to one of their most unlikely American League Championship Series appearances in team history.

But a convincing case can be made that the top reason is manager Alex Cora, who expertly guides his team from his office to the clubhouse to the dugout -- and oftentimes through text messages away from the ballpark -- on a daily basis.

Coming off a 24-36 season in 2020 in which the Red Sox were never in serious contention, the general expectation was for them to make incremental improvements in ’21 and perhaps get to .500 or maybe, if enough things went right, to reach the mid 80s in wins.

While everyone was breaking down the team’s strengths and weaknesses on paper, perhaps not enough people paid attention to something that is hard to quantify: the value of a manager.

What is Cora’s value to the 2021 Red Sox, who won 92 games in the regular season, upended the Yankees in the AL Wild Card Game and then took out the 100-win Rays in a four-game Division Series?

“A lot. I mean, a lot,” said Red Sox left fielder Alex Verdugo. “That guy's amazing. How smart he is, baseball IQ-wise, the way he manages the game and plays with the bullpen; he's playing chess, man. The other team's playing checkers. It's a lot of fun and I'm just happy I can be along for the ride with him.”

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After leading the Sox to a World Series title in 2018, Cora was suspended by MLB last season for his wrongdoing as bench coach in the 2017 Astros’ sign-stealing scandal and he has consistently held himself accountable for his actions.

The Red Sox had to weigh all the various pros and cons before deciding if they should re-hire Cora as their manager.

In the most non-glamorous interview venue imaginable -- an airport hangar in Puerto Rico -- Cora passionately convinced chief baseball officer Chaim Bloom that he was the right man to lead the Red Sox again.

“Obviously, the team is different as compared to last year, but he has [made a difference],” said shortstop Xander Bogaerts of Cora. “He and the guys that came in have recharged us.”

The decision to make the old boss the new boss paid off early and often as Cora changed the vibe of the Red Sox during Spring Training and had them on pace for 100 wins halfway through the season.

And then he gathered his team after they stumbled from the week before the All-Star break all the way through the dog days of August in a 21-27 stretch, at which time the Rays toppled them for the lead in the division.

Most challengingly, Cora gathered his club again when a COVID-19 outbreak decimated the roster (13 players went on the COVID IL) from Aug. 27-Sept. 13.

By getting his team through the regular season and into the postseason, Cora has gotten a chance to again demonstrate perhaps his top attribute: October tactician.

It’s no accident that Cora will enter the 2021 ALCS against the Astros with a postseason record of 15-4, the top winning percentage (.789) of any manager with at least 15 postseason games on a résumé.

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Cora is also 5-0 in potential clincher games. The only manager in AL/NL history who won more clincher games before a loss was Terry Francona, who won his first six -- also for Boston.

“He made a huge difference,” said Red Sox owner John Henry. “You see it every night. You guys watch it every night. He makes a huge difference in the decisions he makes, as in 2018, especially in October -- his instincts and his intelligence in this game is unmatched.”

In the just-completed ALDS, Cora put on an absolute clinic.

Take, for example, Game 2, when Chris Sale gave up a grand slam to Jordan Luplow in the first inning to put the Red Sox in a 5-2 hole and in danger of falling into an 0-2 deficit in the best-of-five-series.

Instead of being sentimental and giving his ace a chance to settle into the start, the cold-blooded Cora gave Sale the hook and went with 25-year-old rookie Tanner Houck. The hard-throwing righty fired five electric innings, which turned the momentum in the series.

Cora also stalked up and down the dugout and told his offense to stay relentless and not get down about what had transpired in the bottom of the first.

“So it was definitely a little deflating at first, but I just remember going into the dugout and A.C. is coming up and down the dugout just, ‘It's all right, we got a whole game, eight more innings. You know, keep going.’ I felt like that really set the tone,” said Verdugo.

The Red Sox bats responded with a 20-hit clinic and a 14-6 win that took the series back to Boston deadlocked.

Then came the epic that was Game 3 in Boston. After more deflation -- Hansel Robles coughing up a two-run lead in the eighth inning -- Cora picked the right guy to get his team through extra innings.

That man was Nick Pivetta, a starting pitcher by trade who had thrown 73 pitches out of the ‘pen in Game 1. Cora kept him out there for innings 10-13 on two days' rest in Game 3, as Pivetta gave the Red Sox 67 huge pitches and set up Christian Vázquez to be the walk-off hero in the bottom of the 13th.

One of Cora’s top gifts is knowing the pulse of his players and how each will respond to a given situation.

“Like I always say, 'He's like a father, brother, manager,' whatever, however you can call it to us,” said lefty Eduardo Rodriguez. “It means a lot to have him. He trusts us. He trusts everybody in that clubhouse. He gives you the chance every time that he hands it to you, and you've just got to go out there and do your job.”

Rodriguez didn’t do his job in Game 1, throwing 41 pitches en route to being lifted after five outs.

But Cora sensed the veteran would bounce back, so he gave him the start in Game 4 on three days' rest. Rodriguez responded with five strong innings, which included just three hits allowed, two runs, no walks and six strikeouts.

By the end of the night, the Red Sox were drinking champagne -- again.

Cora was teary-eyed after the final out as he embraced his daughter Camila, a freshman at Boston College.

What had him so emotional?

“A lot of things. Just proud of the group. Proud of everybody here. Happy for my family that they can enjoy this. Happy for Boston,” said Cora.

Without a doubt, Boston is equally as happy to have Cora back in the big seat for another ride through October.