For two fan bases, for two cities, this is the best time. These are the days that fill those of us in other sporting cities with such envy. Yes, the actual winning of a championship is the culmination of the fan experience. Yes, the parties that come after, the parades, the civic celebrations, those are all an integral part, things to be savored for a lifetime.

But it’s these days and hours leading up when the full fan experience is realized, especially when there is an opportunity to win a championship at home.

Especially that first championship.

St. Louis leads off Sunday night. This is not a city unfamiliar with championships, of course. The Cardinals have won more World Series than any team not called the Yankees. The Rams were as an electric show near the turn of the century as the NFL has seen. The old St. Louis Hawks won one of the two championships the Celtics didn’t win between 1957 and 1969.

But the Blues have been around since the first wave of expansion doubled the NHL from 6 to 12 teams in 1967, and though they made three flukey Finals their first three years — all the expansion teams were lumped in one division those years, meaning, curiously, an expansion team would play for the Cup every time — they never even won a Stanley Cup Final game before now, let alone Lord Stanley’s chalice.

Now they sit one win away, with one game at home on Sunday night to etch their names on the Cup forever. Exciting for the players. And exhilarating for fans who have waited to long, who have bled with the Blues all these years. Between now and the puck drop, all manner of sporting emotions will take over — excitement, anticipation, joy, wonderment. And also fear and paranoia and concern. Nobody wants to be the fan who got too far ahead of themselves, who laid the jinx on the team and the whole city by picturing what a postgame celebration will look like, and sound like.

Sunday at 8 o’clock can’t come quick enough

And what of Toronto? The most ardent of all Canadian hockey cities has gone Cup-less for over half a century, but there was a time in the early ’90s when it seemed the baseball Blue Jays were going to be the team of that decade (before the Yankees rose from the dust to snatch that clean away). Still, as wonderful as those matching titles of 1992 and ’93 have been, its also been a long time since Toronto has sat where it sits now, on the precipice.

Twenty-six years ago, it was a one-day wait between Game 5 of the World Series in Philadelphia and Game 6 in Toronto, and that wound up being worth the wait: Joe Carter touched ’em all, and never hit a bigger home run in his life, just as Sean McDonough predicted.

And then there are the Raptors, up 3-1 in games over the dynastic if depleted Warriors, who swept Golden State in Oakland, and Monday at 9 p.m. will get a chance to bring the Larry O’Brien Trophy north of the border. The home crowds have been remarkable all playoffs long, augments by thick crowds who gather outside the arena to watch on big screens.

What’s going through the minds of fans who have absorbed one playoff failure after another and now are so close they can taste it?

Same as the minds of sports fans in St Louis: Excitement. Anticipation. Joy. Wonderment. And also fear and paranoia and concern. There is no greater time to be a sports fan than in the Moment Before It Happens. And no greater fear that it’ll never happen at all.

Don’t you miss that?

Vac’s Whacks

Every now and again, it’s good to remember that even guys who scuffle in the big leagues are the very best of the very best. Good for Jason Vargas, who’s pitched splendidly for a month now.

Baseball season around here just got 15 percent more fun now that Didi Gregorius has joined in.

I’ll watch just about anything Christina Applegate and Linda Cardellini are in anyway, and “Dead to Me,” the Netflix show that stars both of them, is a quintessential example of why.

Given what a golden baseball age he’s built in San Francisco, it’s almost impossible to believe Bruce Bochy lost his 1,000th game as Giants manager a few days before he won his thousandth.

Whack Back at Vac

Charles Leghoff: Do you see Clint Fraizer and his emotional state as the millenial version of Gregg Jefferies?

Vac: The big difference is you don’t see the outright jealousy/hostility now that you did 30 years ago with Jefferies. But it is definitely a template No. 77 might want to avoid.

Roland Chapdelaine: On the subject of shared nicknames, don’t forget “The Count”: John Montefusco, Sparky Lyle, Count Basie, Dracula, Chocula. And the Sesame Street Count, too!

Vac: I think Chocula really should’ve called his lawyer, no?

Part of what makes me mad about Mickey Callaway is that he’s likeable. He [is] just out of his depth.Every word of this. Every. Word.

Martin Pinchin: Why would you deny a guy with everything … EVERYTHING?

Vac: The more I think about the audacity of Tom Brady thinking to commandeer “Tom Terrific” (which many, many wonderful readers pointed out, was originally a cartoon on the old “Captain Kangaroo” show), the angrier I get.