King County Executive Dow Constantine, who has never met a sports cliché he couldn't make his own, turned to another familiar catchphrase Wednesday morning.

"It's time to put the ball in play," he said while announcing that hedge-fund manager Chris Hansen's arena proposal is officially enticing enough to put to a city and county council vote.

Three months ago, Constantine cautioned, "This is not Game 7. This is the tipoff of the first game of the preseason." My, how quickly things progress when a well-intentioned businessman slaps $290 million on the table. Now it's play ball, and for every long-suffering Seattle sports fan, anticipation of such a high-stakes game must include this reflexive thought:

Don't let us down.

There are legitimate concerns. But Seattle has been a victim of too much disappointment for such a young sports city. Losing the Sonics four years ago ranks as the most notorious and painful. But in a stunning change of fortune, here comes an opportunity to replace a stolen NBA team, add the NHL and build an entertainment palace that can attract A-list performers.

It is a chance to transform Seattle from a city with major-league teams to a true major-league city. Ponder the difference. Then consider that, in the admittedly absurd world of pro sports, this is as fair of a deal as any prospective owner will propose. And ask yourself: Do you really want to look a gift hedge-fund manager in the mouth?

Or more seriously: Do you want to continue to be the little sports city that couldn't? Or do you want to be proactive in elevating this community?

Ultimately, this game will be a test of the city's sports ambition. This isn't just some decent arena plan that figures to be the first of many good offers. Hansen has presented the best deal you'll see over the next decade, maybe longer. The memorandum of understanding — which the city and county councils will scrutinize and vote on soon, perhaps within a month — is pretty much what Hansen proposed initially. It's still a $490 million arena. Hansen is still pledging $290 million and asking for a maximum of $200 million in bonds, which he plans to replay through arena taxes and revenues.

The city's investment would be capped at $120 million, the county's at $80 million. The new wrinkle is the revelation that the deal can work with a commitment from the NBA only, and in that case, the public contribution would not exceed $120 million. The rest of the money would only be available if the NHL committed to come to Seattle.

It's an ambitious, creative and thoughtful deal. The legitimate concerns are all manageable. But when I say legitimate concerns, I'm referring to three things: Sodo District traffic congestion and how it affects the Port of Seattle; ensuring the city isn't taking on too much debt; and figuring out whether Hansen, with all the financial risks he's assuming, has an investment group rich enough to make this work. The group must cover revenue shortfalls and maintenance, establish a reserve fund, not to mention the $350 million to $500 million or so he'll need to buy and move an NBA team.

Hansen should eliminate the latter concern with relative ease. The debt-service issue isn't a problem, either, if the council feels enough of its constituents want this arena. The Sodo traffic is more complicated, mostly because the city deferred a solution long ago and distrust is high. But if all parties realize that it's unfair to use Hansen to solve all their problems and work collaboratively with him to focus on mitigating the issues that a new arena would provide, even that issue is manageable.

"People coming to the city to an event is a good thing," Mayor Mike McGinn said. "I mean, think about it, people. You know, seriously. People coming to the city to work is a good thing. We have a thriving economy with many different bases of jobs and revenue here. And we care about all of them. We don't pit them against each other. We try to figure out how to make them work together."

Once again, consider the big picture. This is a game-changing opportunity for the city. Do you want more of the same? Or do you want more?

If Hansen's arena proposal fails, prepare to watch the Oklahoma City Thunder pursue championships for the next five years from the sidelines, knowing that you had your chance and declined.

If Hansen succeeds, prepare to enjoy a lush Seattle sports scene, the kind you've never had before, the kind that will change the quality of life for every entertainment fiend in the city.

This is your chance, Seattle. The ball is in play. You don't have to be Constantine to know the next appropriate sports cliché.

Step up.

Jerry Brewer: 206-464-2277 or jbrewer@seattletimes.com. On Twitter @JerryBrewer.