Scotland referendum
Pro and anti-independence supporters wave posters outside a campaign event in Clydebank, Scotland, Tuesday, Sept. 16, 2014. The referendum on Scottish independence will take place Thursday, when Scotland will vote whether or not to end the 307-year-old union with the rest of the United Kingdom. Reuters/Dylan Martinez

While the United Kingdom anxiously waits for Scotland to decide on independence, the world's largest betting exchange says it already knows which side will win, and it's willing to put its money on the line. Betfair, based out of London, has already paid out more than 100,000 pounds to gamblers who bet Scotland will choose “No” and keep the UK intact.

There’s a 79 percent probability Scots will choose "No," if the betting patterns on Betfair are correct. That’s a significant majority compared to polls in recent days, which show voters are evenly split. The two most recent polls show the "No" vote winning by seven points, but a poll last week showed the "Yes" vote winning by that same percentage. Anywhere between 5 and 17 percent of Scots are undecided, based on poll data since Sept. 1.

“We’ve decided that ‘No’ is most likely to be the winning vote in three days time, so we’ve put our money where our mouth is,” a Betfair specialist told Reuters.

Betfair is only paying out on its much smaller “sportsbook” service, where Betfair itself makes the odds. The sportsbook service makes up only 9 percent of Betfair’s annual revenue, so it is indeed a low-risk publicity stunt, according to the Financial Times. Betting houses will often pay out early in contests they see as a done deal to drum up publicity.

Betfair’s odds for a "No" vote are one to four, so any "No" betters will get a payout of a quarter of however much they bet. For example, if you bet $100 that Scotland would choose "No," Betfair is paying you $125.00. On the more riskier side of the coin, Betfair has 11-to-4 odds that Scots will get a last-minute boost of patriotism and break off from the UK. So a winning $100 bet on "Yes" would get you $375.00.

An hour after tweeting out the announcement that it would pay up, Betfair reminded followers that it called the 2012 U.S. presidential election to a startling degree of accuracy. Betfair regularly hosts bets on political campaigns, particularly in the UK.