For Jason Heyward, there’s one thing that always stuck about his former teammate, Jake Arrieta.

“Just the fact that he always had the confidence no matter what,” Heyward said on Tuesday, a day after Arrieta announced his retirement. “No matter what game, no matter our odds, our situation, every time he went out on the mound he wanted to win. He expected to win.”

No game better captures that than the 2015 NL Wild Card Game against Pittsburgh. In a do-or-die game, Arrieta wanted to pitch and turned in one of the most dominant pitching performances in the playoffs by a Cubs pitcher. Arrieta pitched a 5-hit shutout, striking out 11 as the Cubs beat the Pirates 4-0.

“When I think about Jake, he wanted the ball in the biggest games,” Cubs president of baseball operations Jed Hoyer said. “His kind of airplane speech that he made to everyone about, ‘You guys get in and I’ll take care of the rest,’ I think that meant a lot to a young team.”

It was the breakthrough moment for the Cubs’ core that would go on to win the 2016 World Series.

“As far as us winning the World Series, yeah I don’t think you can say there was a bigger acquisition,” Hoyer said.

That’s because of his epic trajectory. Acquired in a trade with Pedro Strop for Scott Feldman and Steve Clevenger in 2013, Arrieta was a struggling power-arm starter. Prior to being traded, he had a 7.23 ERA and a 1.775 WHIP with the Orioles.

The move to the Cubs was a fruitful one for both sides. In 2014, Arrieta pitched to a 2.53 ERA and 0.989 WHIP in 156.2 innings and finished 9^th in NL Cy Young Award voting.

“Very clearly when we acquired him, we thought we were getting a power arm from Baltimore that sort of haven’t met his potential there and we hoped that a change of scenery would do him a lot of good,” Hoyer said. “Never in our wildest dreams did we imagine that he was gonna hit the heights that he did.”

That’s because the heights he reached in 2015 were elite. That run of dominance he went on in 2015 and 2016 is what makes it so hard for David Ross to pick a favorite memory of Arrieta.

“I’ve got a lot. That one time he was awesome. Like that entire year,” Ross said with a laugh.

Across the second half of 2015 and the early part of 2016, Arrieta made 29 starts and went 24-1 with a 0.99 ERA, a 0.74 WHIP, 5 complete games, 4 shutouts and a pair of no hitters. He allowed just 23 earned runs and 4 home runs in that time. He won the 2015 NL Cy Young Award.

“I mean you appreciate excellence like that,” Heyward said. “For him to come in and just be the opposite of Jon Lester coming in the next day, it’s like, ok, you get the past the world champion and here you go, you get to face a Cy Young, a guy who’s thrown a couple of no hitters. It just gave us that much more depth, more intensity when he took the mound.”

 Just as importantly as his pitching prowess was the teammate he was.

“I can’t say enough about him and what he’s meant to me,” Kyle Hendricks said. “When I came up, just the leader, the mentor that he was for me, pulling me to the side, teaching me how to be a pro, teaching me about the game, he had such a huge impact on me and my career.”

Arrieta will go down as a special member of the Chicago Cubs’ history.

“Someone like Jake came here when things weren’t going great, immediately and was a part of a quick turnaround and then you see the ultimate goal happen in the third year he’s here,” Heyward said. “What he’s done, his numbers in this uniform speak for itself and his intensity every day when he stepped on the mound, no questions asked.”