CHICAGO — Travis d’Arnaud homered off the Big Apple in center field at Citi Field in Game 1. Twenty-four hours later Noah Syndergaard overwhelmed the Cubs and the Mets had a two-games-to-none lead in the NLCS.

The first two games of the series emphasized — if indeed the point needed emphasis — just what a winning trade Sandy Alderson made nearly three years ago when he cashed in a chip named R.A. Dickey.

From Feb. 2, 2008, when the Twins dealt Johan Santana to the Mets, to July 30, 2015, when David Price was moved from Detroit to Toronto, a former Cy Young-winning pitcher was traded 15 times, including Cliff Lee and Jake Peavy three times each and Price in each of the past two Julys.

The full results are not in on these trades — particularly those last two for Price — but two stand out for maximizing returns and, lo and behold, the winners of those trades currently lead each of the League Championship Series and may face each other in the World Series.

On Dec. 19, 2010, the Royals turned Zack Greinke and Yuniesky Betancourt into Lorenzo Cain, Alcides Escobar, Jeremy Jeffress and Jake Odorizzi. Cain is the center fielder and Escobar the shortstop for the defending AL champs while Odorizzi was part of a package spun to Tampa for former Kansas City ace James Shields and current closer Wade Davis.

Almost two years to the day, Dec. 17, 2012, the Mets finalized a deal in which they sent Dickey, Josh Thole and Mike Nickeas to the Blue Jays for d’Arnaud, Syndergaard, John Buck and Wuilmer Becerra.

The trade was widely praised for the Mets in real time and is lauded even more now in retrospect.

And the trigger to the deal was essentially the same reason why the Blue Jays obtained Price this past July:

As with Price this year, Toronto felt its rotation was crying out for a bulldog ace (remember Dickey had just won the Cy Young a few months earlier). As with Price, the Blue Jays had not been to the playoffs since winning the World Series in 1993. They saw that rare instance when the AL East opened up because the Yankees and Red Sox were simultaneously vulnerable. Then, like now, they did not want to waste prime years of Jose Bautista and Edwin Encarnacion when both were on team-friendly contracts, and generally believed they had a window with a win-now core.

“By the time d’Arnaud and Syndergaard would emerge, we would be beyond that window,” Toronto general manager Alex Anthopoulos recalled by phone. “So we had to decide do we trade guys like Bautista and Encarnacion and take a step back with kids or do we try to capitalize in the here and now?”

Toronto talked to the Rays about Shields, but felt Tampa Bay was not going to trade him within the division. The Jays only liked one high-end free-agent starter, Anibal Sanchez, but their organizational policy not to go beyond five years with a free agent and Sanchez’s desire to stay in Detroit doomed those chances.

Thus, for the Blue Jays, it was Dickey or no one. That was one advantage the Mets had in making this deal. Also, as with Price, the Blue Jays were all in and couldn’t stop. In mid-November 2012, they had given up a bevy of prospects to Miami for Jose Reyes, Mark Buehrle and Josh Johnson. They felt to finish off a no-doubt contender they needed something approximating a No. 1 starter, and Toronto believed Dickey had mastered the knuckleball to take away some of the fickle nature of the pitch.

In addition, Dickey was due just $5 million for 2013 and was willing to do a team-friendly extension — two years at $25 million with a 2016 option. Toronto was not doing the deal without getting four years of control.

Want another plus for the Mets? J.P. Ricciardi had been Toronto’s general manager and Anthopoulos his assistant, so the two had a comfortable relationship and could cut out the extraneous tension in so many deals.

In addition, because the Mets had made the Carlos Beltran-for-Zack Wheeler swap the previous July and that had gone so well, they were fully self-assured to do an established-player-for-prospects deal again.

“The Beltran trade emboldened us,” Mets assistant GM John Ricco recalled. “It really taught us the process how to do this kind of deal. It gave us confidence that if you did one, you can do another.”

What the Mets had most of all as an advantage — and used well — was leverage. Because Dickey was due just $5 million in 2013, they could just keep him to help protect a rotation that would eventually incorporate Wheeler and Matt Harvey in 2013. They could extend him. They could revisit a trade in July. So they either heard exactly what they wanted or they would not move the player.

At the November GM Meetings, Anthopoulos was left with the impression the Mets were not motivated to move Dickey. But at the Winter Meetings the following month, the tenor had changed.

The Mets were talking to Texas about a deal for Dickey built around Mike Olt and with Baltimore about a deal headed by Dylan Bundy, though the Orioles mainly teased and never jumped fully in.

The Mets let Toronto know that it was going to take two frontline prospects to get a deal done, and because their need for a young catcher was so overt that it would be a non-starter without d’Arnaud. The Blue Jays knew how this worked: When they had traded a Cy Young winner, Roy Halladay, to Philadelphia three years earlier, d’Arnaud was one of the key pieces.

Toronto had taken Aaron Sanchez with the 34th pick in June 2010 and Syndergaard four picks later. The Mets liked both, but Sanchez had an elbow issue during the 2012 season, so the Mets focused on Syndergaard. You see how these trades could go wrong. Sanchez has not developed like Syndergaard, Olt never fulfilled his lofty projections and injuries have derailed Bundy.

The Mets included Thole because he could catch a knuckleball and asked for one more prospect, willing to take a lottery ticket in Becerra, an outfielder who was just 18 when the trade was made. The Mets internally look at Becerra now as falling between their 10th- and 15th-best prospects.

Dickey, meanwhile, has been a bulldog for Toronto, but lacking the excellence of that final Mets season. He is starting Tuesday’s ALCS Game 4 for the Blue Jays, mainly because Toronto did not have a better alternative. Nevertheless, because of his ability to give innings, the Blue Jays are expected to pick up his $12 million 2016 option. Meanwhile, d’Arnaud has established himself as a high-end offensive catcher and Syndergaard arguably has the best stuff on a rotation full of great stuff.

“From the process standpoint, we feel good about that trade,” Anthopoulos said. “It did not work out how we hoped as far as winning in 2013 and ’14. R.A. led us in wins and innings those two years. For us, it was like giving up [well-regarded prospect Daniel] Norris for Price. We think Norris is going to be terrific and [Matt] Boyd is going to be good, too.

“You have got to give yourself a chance to win, and to do that, you have to give up talent.”