It's a Saturday night at my local casino.

You've got craps, blackjack, insane carpet design, no windows, of course, and that constant, constant noise from the slot machines.

But the noisiest corner tonight is at the far end of the casino floor, the latest addition

to the place, and you can't miss it.

A giant blue orb hangs from the ceiling.

It's surrounded by a ring of 16 massive TV screens, and below that is a never-ending

scroll of text winding its way around the room,

names, numbers, stats that seem to never, ever repeat.

The best thing I could compare it to is the set of a cable news network on election night,

or maybe the floor of the New York Stock Exchange.

That big blue orb tells us what it actually is, the sports book.

Tonight you've got World Series baseball, Yankees and Dodgers,

as well as a Celtics game and a Bruins game,

not to mention a half dozen college football games, all competing for eyeballs and dollars.

The money line on the Yankees right now is plus 4.10, meaning for every dollar you bet,

you'll get back $4.10 on a win. Not bad, but obviously I'm not going to bet for the

Yankees. We're in Boston. So mostly I sit back and try to figure out which of the many

games people here are actually cheering for. And also wonder, are they cheering because they're fans or because

they've got money on the line?

Most Americans can find some version of this scene where they live.

And that, let me tell you, is a very new thing.

Just a few decades ago, outside of Las Vegas and the racetrack, gambling was illegal.

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