Betting on sports in the United States has always been a pretty simple proposition: Call your bookie or go to a Las Vegas sportsbook before the game starts. Place your bets. And pick up your winnings or tear up your ticket – depending on whether you won or lost.

That’s about to change.

Cantor Fitzgerald, whose technology drives about $500 billion in transactions for the world’s capital markets every day, now offers in-game betting at the Venetian and Palazzo through its affiliate, Cantor Gaming. That’s right: in-game betting.

It’s a pretty simple concept. At most sportsbooks, once the game starts, the betting ends (except for things like second-half lines). At sportsbooks operated by Cantor Gaming, once the game starts, the betting has just begun.

If you think a team is going to score a touchdown on a particular drive, place a bet. If you think a team is going three-and-out on this possession, place a bet. Cantor’s in-game betting provides a non-stop stream of betting options as you watch the game. The bets are delivered to a special electronic device, so all bettors have to do is punch a button and let it ride.

Not only does this allow bettors to show up late for a game, it also allows them to hedge or double pre-game bets. If the Colts are up 7-0 on the Jaguars, you get fresh odds. If the Giants are up 31-10 on Philadelphia when you walk into the bar, and you think the Eagles will come back to win, you'll have fresh odds on that – and lots of money after the game.

Cantor’s system also provides an equalizer in case of injury. If you bet the farm on the Packers over the Lions, and suddenly Aaron Rodgers gets a concussion, you can now hedge by betting on Green Bay to get stuffed by Ndamukong Suh.

Similarly, there might be games you have no feel for whatsoever. But after watching the teams play for a quarter, you can see where the game is going and place a bet then. It’s similar to what I did with second-half lines at the Wynn during the first weekend of the NCAA basketball tournament. I placed bets on seven second-half lines, and I won all of them. The only difference is that a human set the second-half lines for those games, while a computer is constantly generating lines for in-game betting.

The other bets you can make with in-game betting, such as whether Peyton Manning will throw an interception on a particular series, or will the field goal kicker miss this PAT, or will the next play be a running or passing play, are like all basic prop bets. They’re fun. They're entertaining. And they’re kind of the equivalent of penny slots – you can spend a lot of time and not a lot of money.

I tried the Cantor device once with a friend of mine at Lagasse’s Stadium in the Palazzo. (More accurately, he tried it and I offered suggestions.) He bet on the Colts to go three and out -- and then looked up at the screen to see Dallas Clark catching a long pass. He was out $20, and I was glad it wasn’t my bankroll. He placed a couple more bets on other plays that day and decided it wasn’t for him. In-game betting took away from his enjoyment of the game. But as I looked around the bar, I could tell he was in the minority.

Every seat, couch, chair and suite in Lagasse’s Stadium was filled with patrons who weren’t just staring at the screen and then down at their betting tickets. They were placing bets, and they were having a good time doing it. Within seconds of a play ending, bets were being offered on the next play, bets were being accepted and bets were being paid out on previous plays. Talk about an incentive to stay for the whole game; garbage time is one of the best times to wager on the outcome of a play.

I tracked down Andrew Garrood, who helped develop the algorithms and technology that powers Cantor’s in-game betting. Garrood, now the executive director of Las Vegas Sports Consulting, a sports handicapping service owned by Cantor, explained the system to me, and I have to admit, he made it sound simple. Basically, Cantor uses historical data to predict what will happen in the financial markets. So they’re taking that same principle -- using the past to predict the likelihood of events in sports -- and applying it to bookmaking. It makes you wonder why no one thought of this before.

“We’ve been pricing financial markets for years,” Garrood says. “For example, will the Dow Jones go up or down in the next two minutes? Will the value of the euro go up or down? Everything we’ve learned in terms of technology, matching buyers and sellers, pricing engines – it’s an aggregate of our understanding on all of these fields that helped us to build a sports wagering model in Nevada.”

Is it really that simple? Isn’t there much more uncertainty in games than in the market?

“Games are different than the stock market, but there are some similarities,” Garrood says. "Volatility and psychology drives the pricing of markets, making them bullish or bearish. The same is true with a sporting event. Ask 100 people who the favorite is in a game and a strong consensus will say the Falcons will beat the Panthers. The disagreement comes in by how much. That’s where the math comes in. As the game evolves, you’ve seen every situation (historically speaking), you see what happens when they’re ahead by those scores, what happens in those situations, and you can quantify them. You can build algorithms that will price all of those events. With all of that historical data, you can generate pricing for football, basketball, hockey or soccer or any sport. It can all be quantified.”

In fact, what Cantor can quantify based on historical data is pretty amazing.

“Most of the plain vanilla events are much simpler to predict,” Garrood says. “Like if a drive starts at the 20-yard line, what’s the likelihood of scoring a touchdown or field goal? Or if they punt the ball, what will be the ball position for the other team?”

But even the best computer models run into situations where it’s tough to predict what’s going to happen. No one saw Bill Belichick’s famous 4th-and-2 call against the Colts coming. And good luck placing an algorithm on Les Miles in the 4th quarter. “Coaching calls complicate things,” Garrood says. “Mathematically, [Belichick] was right. But the risk of getting that call wrong is so high most coaches won’t make it. I suspect that in a few years’ time, every coach will make that call because everyone will have done the math.”

So much for “Any Given Sunday.” And if you get a little overwhelmed by how quantifiable games can be, just wait. This is only the beginning.

“The number of markets you can actually price are limitless,” says Garrood. “The only limit is human fantasy -- a two point or three point shot by the Pacer or Celtics, how many yards will the running back go for, how many will the quarterback pass for. There is genuinely no limit to what you can offer. Capacity is the issue. How much can you display? There’s a limit to how much the human being can absorb.”

This will change the way many fans watch sports – just like fantasy football has changed the way many of us follow the game. But here’s the huge difference: In fantasy football, fans don’t care what the team does as long as the individual succeeds. With in-game betting, individual decisions fall away and leave mathematical patterns to rule the day. This clears the way for an entirely new generation of fans. Just like a segment of stock pickers look only at charts and don’t know (or care) what the companies do, a sector of football fans will rely fully on historical precedent and ignore the names, numbers and colors on the jersey.

“Most plays don’t really matter,” Garood says. “Increasingly as I watch sports, I’m trying to watch to identify the critical play. I’d like to know the critical play before it happens. It can be quite simple, like the 4th first down. Getting another first down could be the dagger, making the defense tired etc. And I wonder, ‘How do I monitor those patterns?’”

That’s exactly the type of thought process that can give you an edge. If you can identify the critical moment in the game, you can make the wager that will make you profitable for the day. And if you get that moment right, you can spend a few hours enjoying what still has most bettors sweating bullets – the end of the game.