Suspend belief for a moment. Ignore the imminent reality that is the 2012 Summer Olympics in London. Allow yourself, instead, to imagine an alternate sporting universe:

It is the year 2012. Tim Tebow has just purchased an apartment on Manhattan’s Upper West Side, a short limousine ride from his new home stadium, just southwest of Times Square. The Jets are preparing for their fourth season at Goldman Sachs Field, where the New Orleans Saints lost Super Bowl XLIV when organizers left open the roof and Drew Brees’s high-powered offense was slowed by below-freezing temperatures. The Mets and Yankees have only just finished construction on their new stadiums, after the exclusion of baseball and softball from the Olympic slate made the facilities unnecessary for New York’s hosting of the 2012 Summer Games. The Giants, demoralized by being left behind in New Jersey and becoming New York City’s no. 2 football franchise, never make it to Super Bowls XLII and XLVI. Tebow was in Goldman Sachs Field — rebranded, for two weeks, as the Olympic Stadium — along with hometown favorites Dwight Howard and LeBron James as they watch the Martin Scorsese–directed Opening Ceremony. Howard had joined the Nets a year earlier, with the enticement of the team’s Frank Gehry–designed Brooklyn arena and the opportunity to battle in the same city with LeBron James. James is welcoming his Team USA teammates to Madison Square Garden, where he plays home games as a member of the Knicks, having been wooed by the arena’s lavish Olympic renovations and the chance to call the Olympic basketball arena his home. James, Amar’e Stoudemire, and Carmelo Anthony have just won their first NBA championship.

This is but one version of events, some more likely than others, as they might have happened if the 2012 Summer Olympics had been granted to New York. In 2005, New York and London were two of five cities, along with Moscow, Madrid, and Paris, bidding for the Games. The bid would have produced an altered sporting landscape in the city, with many unforeseen consequences. Some of that development has come to fruition. Much of it remains only in plans. “Much of what we wanted has been done,” Alex Garvin, an urban planner and lead designer on the New York bid, said. “Still, I really wanted to see the world on the boardwalk on Coney Island looking out at the sailing races. It would have been spectacular.”

To understand the impact the Olympics would have had on New York, as well as the impact the losing bid has had, even without the Games, it’s useful to trace the conception and development of the West Side Stadium. When Jay Cross joined the Jets to head development in 2000 (he became team president the next year), his first meeting was with Dan Doctoroff, a private equity manager leading New York’s Olympic bid. After a failed effort by the Yankees to build a new stadium on an undeveloped rail yard north of Madison Square Garden, Doctoroff swooped in to propose the site as a location for an Olympic stadium. (Doctoroff, currently the CEO of Bloomberg LP, has succeeded at nearly every stop in his career but this one. He declined an interview request.) Doctoroff hoped to avoid the empty, leftover stadiums that plague so many post-Olympic cities, so he needed a tenant to take over the stadium. The Jets were interested. “The driving force for the Jets was a move to New York City,” Cross told me recently. “Sharing a facility with the Giants, while it’s proven to be possible at the New Meadowlands, is not optimal from a team culture point of view.”

The Jets agreed to shoulder much of the cost of the new stadium, which would have been completed in time for the 2009 NFL season, hosted the 2010 Super Bowl, and, when the time came, be converted to host the Opening Ceremony, track and field, and seven other Olympic events. Mayor Michael Bloomberg, who had canceled tentative stadium agreements reached between the city’s two baseball teams and his predecessor, Rudy Giuliani, supported the football plan. He bartered for support from an otherwise hesitant West Side community by pledging not to tear down the High Line, an elevated railroad that was scheduled to be demolished but had become a cause célèbre to residents of Greenwich Village and Chelsea. (It has since become a much-loved park.) “The West Side Stadium would have been first, as the priorities went,” Cross said. “Second, third, and fourth would have been the Nets, Mets, and Yankees.”

Then Jim Dolan got involved. In 2004, his company, Cablevision, which owns the Knicks, Rangers, and Madison Square Garden, began advertising against the stadium. One study found that Cablevision spent $22.1 million on anti-stadium advertisements — more than the Olympic planning committee spent advertising its entire bid. The attacks worked. On June 6, 2005, one month before the bid was to be presented to the IOC, the state’s two most powerful legislators, Sheldon Silver and Joseph Bruno, rejected a request for $300 million in state funding. The Olympics were left without a stadium.

In just 72 hours, a new plan was developed. Olympic organizers approached the Mets with the possibility of building a stadium in Queens, next to Shea Stadium, for use by the team once the Olympics ended. (The Jets had originally identified Flushing as a possible site for their stadium, and briefly entered discussions with the Mets to build a dual-purpose facility that would host both teams and the Olympics.) The Mets, like the Yankees, had spent years unsuccessfully lobbying the city for a new stadium. With the Olympic bid in crisis, the city moved quickly to an agreement with the Mets. Had the plan been accepted, the Mets would have spent the 2012 season alternating home stands with the Yankees in the Bronx. The Yankees had no interest in assisting the Mets’ stadium push without getting something of their own. Three days later, the city reached a similar agreement for a new Yankee Stadium in the Bronx.

All of a sudden, a decades-long debate over new stadiums in New York City had been resolved in just a week. “Without the immediate need to find a substitute for the Olympic stadium … the issue [of the baseball stadiums] might have continued unresolved for years to come,” Mitchell Moss, a professor of urban policy and planning at New York University, wrote in a paper titled “How New York City Won the Olympics.” Even an earlier threat by George Steinbrenner to take the Yankees to New Jersey, no matter how serious it was, had not moved the needle in the way the Olympic bid had. Suddenly, the West Side Stadium was dead, and the Mets and Yankees had new ballparks. “The politics of it were, ‘Whatever the city did for the Mets, the Yankees demanded the same treatment,'” Cross, who left the Jets in 2008, said. “That put the city in this mad scramble to please the Yankees, Mets, and then the Jets. We got left behind.”

But was the West Side Stadium really dead? Alex Garvin, the Olympic bid’s lead planner, said it wasn’t. “We always intended, if we won, to push for the West Side Stadium again,” he said. “We believed that [State Assembly Speaker] Sheldon Silver would come around if the Olympics were a reality.” The bid planners, according to Garvin, would have made a second attempt at securing state funding for the stadium, with the Jets as the primary tenant. If the stadium had been built, the proposals for its use could have been limitless. Cross said there were plans to host major college football games and an annual match between the winners of Europe’s Champions League and South America’s Copa Libertadores. There was talk that the stadium could attract the first Premier League team outside the U.K. as an additional tenant. And, of course, the Jets would be in Manhattan. “Location does matter,” Cross said. “If the competitive records were equal, to be the New York team would be an advantage, just the way the Knicks and Rangers have had an advantage over the Nets and Devils … [Tebow] would have been God’s gift to sports in Manhattan.”

Now, there is no stadium, just as there is no Olympic-quality equestrian center in Staten Island, no white-water kayaking course in Queens, no velodrome in the Bronx. Each of these facilities would have been world-class, and, the organizers like to say, would have turned New York into a center of national athletic training and competition. “There’s a lot of sports that New Yorkers play beyond basketball and football,” Cross said, envisioning the city spawning a new generation of Olympic talent. Despite its self-declared title as the center of the universe, New York is not as well-equipped as some smaller cities to host certain major sporting events. This is one reason why many U.S. national championships end up in San Antonio or Indianapolis. “There are a number of events and championships that would love to come to New York, but the city doesn’t have some of the unique facilities to support them,” said Jerry Anderson, who consulted on both the New York and London bids as a designer at the sports architecture firm Populous. “If these Olympics had occurred, it would have left the legacy to support national or international sporting events.”

What is notable about New York’s failed bid is how much of it has been actualized. “The bid was designed so that, win or lose, we would be able to get done the bulk of what we wanted to do,” said Jay Kriegel, the bid’s executive director. Dan Doctoroff was named deputy mayor, a position that allowed him to pursue many of the Olympic projects he had already begun. It’s possible to look at what has happened in New York and determine that, by and large, the city received many of the benefits of Olympic development without enduring many of the negatives such as cost overruns, security concerns, and an inconvenienced populace. The Barclays Center, which would have hosted gymnastics, was built. The Mets and Yankees, of course, got their new stadiums.

The changes have been even more significant beyond sports, driven in large part — close your ears, non-urban policy geeks — by the rezoning of large swaths of New York City. A once-dilapidated section of the Queens neighborhood Hunters Point, meant for the Olympic Village, was rezoned and is now dotted with apartment buildings. A vacant waterfront area in Brooklyn meant for beach volleyball was turned into a park. An extension to the 7 train, first proposed in the Olympic bid, is under construction and will open up Manhattan’s West Side, which, yes, was also rezoned. Since the demise of the Olympic bid and stadium plan, the West Side has seen the construction of high-rise apartment and office buildings, the opening of Clyde Frazier’s Wine and Dine, and a mixed-use development that, when completed, will be New York’s largest such project since Rockefeller Center. “Doctoroff, by the time he gets done, will have a greater impact on this city, I think, than Robert Moses,” Mayor Bloomberg told the New York Times, referring to New York’s mid-century “master builder,” who himself had advocated for a 70,000-seat stadium on Randall’s Island, in the East River, capable of holding Olympic events. “We don’t need the Games,” Mitchell Moss, the author of “How New York City Won the Olympics,” said recently. “The city is a constant series of contests. We just had the triathlon, the U.S. Open in August, then the marathon in November. People in New York are playing tennis and Ultimate Frisbee and golf. We have more walkathons than any city in the world. As for the Olympics, we got everything that really mattered.”

Would the Jets be a better team in Manhattan? And what about the Giants, alone in New Jersey, with a stadium decked out in their colors? Would the Nets’ lineup be different if their arena were already finished — if they had moved to Brooklyn sooner? Would the Mets and Yankees have new stadiums without the Olympic push, and if so, would they look any different? All of these questions are impossible to answer definitively, although similar questions will return as whispers emerge that the city might bid for the 2024 Summer Olympics. (It is all but impossible for New York to host a Winter Olympics, unless an artificial ski run could be constructed from the tip of the Empire State Building to Grand Central Station.) San Francisco, Dallas, and Los Angeles have been rumored as other possibilities, but the actual consideration of bids is still several years away. “Of course we could do it,” Alex Garvin, the lead planner on the 2012 bid, said. “We’ve got all the hotel rooms you need. We have a subway system that can move 500,000 people a day on off-peak hours. Maybe in 2024 the demand for soccer could warrant another stadium.”

The Olympic stadium, along with the fact that, perhaps, the city has simply moved on, would be one of the major obstacles to a future bid — both of the proposed sites for the 2012 stadium are now otherwise occupied. “There is no city that needs an 80,000-seat track stadium,” Jerry Anderson, of Populous, said. “The more likely thing to do is find a piece of grass or asphalt for a temporary facility. Could it be adjacent to Citi Field? Could it be over at the Meadowlands? This would be sacrilege, but could you put it in Central Park, knowing it was temporary? If you want the Olympics, those are the questions you have to ask yourself.”

Correction: A previously published version of this article stated that Dan Doctoroff was named deputy mayor of New York after the IOC vote, when in fact he was already deputy mayor before the vote took place. The text has been corrected.

Reeves Wiedeman is a member of the editorial staff of The New Yorker, and writes the magazine’s Sporting Scene blog.