What's Plan B with Raiders Las Vegas stadium deal on shaky ground?

Sorry to ruin the suspense, but the Raiders will wind up playing at Levi’s Stadium. Within two years, is my guess.

Sources? I don’t need no sources. I can add two plus two, using my solar-powered abacus.

Do the math along with me:

--Raiders’ owner Mark Davis is getting Las Vegas’d. He thought he had a deal for a new stadium, but now his project partner, casino mogul Sheldon Adelson, doesn’t like the deal Davis proposes and has proposed one of his own.

Adelson said, "So I told my people, 'Tell (the Raiders) I could live with the deal (Adelson is proposing), I could live without the deal. Here's the way it's gonna go down.’ If they don't want it, bye-bye."

The dreaded Neon Bye-Bye!

Initially Adelson wanted a piece of the Raiders in return for his own $650 million stadium kick-in and his work arm-twisting Nevada to cough up $750 million.

But Davis is loath to sell any piece of his team. Now Adelson has countered with other demands. I get the feeling Mr. Mogul believes Davis thought Adelson was swinging all his weight and wallet out of the kindness of his heart.

Casino moguls don’t do that.

--If the Vegas deal falls through, how about Oakland? Mayor Libby Schaaf won’t buy the Raiders a new stadium. Her stance is backed by fiscal sanity and a recent poll in which Oakland voters said that keeping the Raiders is far down their list of priorities, below even keeping the A’s--a team run by profiteers and stocked with vagabonds.

That poll was a gut punch to Davis, who believes that everyone on the planet loves his Raiders.

--If Oakland falls through as a stadium site, the best option is Levi’s. The 49ers will be motivated to rent to the Raiders, since the 49ers’ master plan--decades of sold-out games--is springing major leaks.

The NFL will be motivated to encourage and broker a stadium-share deal. The League is sick of the Raiders’ mess, on and off the field, and is facing the reality that it’s getting harder to extort free stadiums from football-desperate cities run by lap-dog politicians.

Sing it with me, Raider Nation: “Levi’s Stad-ium, open your golden gates, Raiders will be your mates, we’ll all have fun!”

Scott Ostler is a San Francisco Chronicle columnist. Email: sostler@sfchronicle.com Twitter: @scottostler