With one hundred percent certainty, only the betting provider wins in a sports bet. A mathematician from Berlin knows an option that promises sure profits as long as few people know about it.
Actually, I shouldn’t write about it. I should keep it to myself, because I was at the Technical University of Berlin and there I met a mathematician who promised me what is actually impossible: a bet where you can’t lose, you can only win.
The atmosphere matches what Wiebke Wittmüß tells us. The graduate mathematician sits in a dilapidated concrete block on Straße des 17. Juni in Berlin and talks about the infallible sports bet. You’ve often heard something like this: the investment with utopian high returns without any risk – mostly offered by shady guys in gloomy back rooms.
Sports betting with guaranteed winnings already has a certain tradition in this city. A few kilometers away, less than two years ago, in a Charlottenburg café, shady mafiosi were working on the results of matches, which Bundesliga referee Robert Hoyzer then had to implement with a whistle, his eyes closed and drawing cards. Hoyzer received a plasma TV for his services and was later convicted.
The 28-year-old Wittmüß has nothing to fear. She doesn’t need Hoyzer or a corrupt goalkeeper: her mathematical acumen is enough. A friend gave her the idea of a 100% sports bet. “It was a boxing match between a German and an Australian,” she explains.
Her friend followed the betting odds at Betandwin and at an Australian online betting agency. And lo and behold: in Germany, the majority bet on the German boxer to win, while in Australia, the majority bet on the Australian. The betting odds were correspondingly different. Among the insiders, this process is known as sure betting or arbitrage.
Wittmüß has not personally checked the matter online. I have not come across any such cases during random checks in various online betting shops. The odds differed only slightly. But whatever, it’s too much practice. Mathematicians deal with something else.
175% return!
This effect, which his friend had reported, should be wonderfully exploitable, thought Wittmüß. “One bets in Germany on the victory of the Australian and in Australia on the triumph of the German at the same time.” Whatever the outcome of the battle, the winner is always the betting machine.
Numerical example: Suppose the odds at the German betting shop are 4 to 1.1 for the Australian and 3.5 to 1.25 for the German in Australia. So you bet one euro on the Australian in Germany and one euro on the German in Australia. It costs exactly two euros. You win 3.5 or 4 euros, a return of 175 or 200 percent.
Stockbrokers who promise such things are considered windy. Wittmüß seems anything but windy. He is familiar with financial mathematics as well as robust optimization.
Isolated betting community
Of course, the competitive gimmick only works, Wittmüß explains, because the games are played in parallel in two communities isolated from each other. In Germany, the Australian is more of a nobody; almost no one speaks German Down Under. “When all the people are well informed, there is no certainty of victory.” In fact, hundreds of boxing fans suddenly betting on their husband’s defeat would lower the odds – the certainty of victory would be overcome.
The principle of certain victory can also be applied to football betting, but with the peculiarity that footballers sometimes tend to be unable to decide and separate with a draw. This is rather unattractive from a mathematical point of view.
“For example, I could bet on the Germany-Poland match at a German and a Polish sports club at the same time,” says Wittmüß. The respective preferences should ensure different betting odds, which the lay betting expert then coldly exploits.
Take advantage of small odds differences
In fact, club bets would be particularly suitable for foolproof sports betting, as they tend not to be so closely tied to the odds on the Internet. Incidentally, slightly different odds are sufficient for a safe return – these do not have to be opposite, as in the case of the two boxers.
For example, at a bookmaker, the odds that Team A will beat Team B are 4.0 to 1.2. The odds are not necessarily the same. With another provider or with your sports club you are less optimistic: the odds are slightly lower, for example 2.5 to 1.5. In both cases, the majority bet on A to win, even if with different odds.
Surprisingly, it is enough for a safe bet: With the first provider you simply bet 1.5 euros on team B and with the second 4.0 euros on team A. Whatever happens, the win is exactly 1.5 * 4.0 = 6.0 euros, the bet is 4.0 + 1.5 = 5.5 euros. You earn at least 50 cents – for sure.
If you like it better as a formula: The winnings of a * b must be greater than the stake of a + b. Of course, this can only happen in two different betting systems isolated from each other, because otherwise the betting provider would suffer losses. So if you find such isolated systems, it is better not to make a fuss, bet some money and calmly wait for the sure profit.
Berlin mathematician Wittmüß has something else in mind. “I’ve never bet, I’m too lazy.”
In contrast, I can only agree. Instead of spending hours comparing odds in dozens of betting shops, I prefer to play volleyball or go jogging. I always hope for a safe (weight) loss.
Correction: In the first version of this text it was wrongly stated that Wiebke Wittmüß had discovered the trick of the sure bet. This is not true, it was a misunderstanding. Sure bets or arbitrage have been known for a long time. Special websites monitor differences in betting behavior and offer sure bets.