The odds of a coin flip are not 50:50

heads or tails? If you can't choose between two options, you'll often throw one away currency. While this is fair, at least in theory, in practice, according to the latest research, there is a preference for one side – even if only slightly.

Over 350,000 coin flips

František Bartos, a PhD candidate at the University of Amsterdam, investigated whether a coin toss has a 50 percent chance of showing either side. This is what he was recruited for 47 volunteerswho tossed coins into the air for more than 12 hours and recorded the score as they landed. 350,757 coin tosses It came like this.

Result: in 50.8 percent After the drop, the same side of the coin was facing up as it was before the toss. Data on the preprint server arXiv.org Its publication cannot be a mere coincidence. “We can be fairly certain that there is statistical bias in coin flips,” Barto says.š the opposite American Scientific.

Minimum rotational deviation

The reason for this is not yet completely clear. The common theory for this minimal feature comes from one Stanford study From 2007. If you throw a coin in the air, its path and spin can be calculated, at least in theory. For a perfect coin, the probability of it landing heads or tails is exactly 50 percent. However, most coins are not exactly related to their currencies Symmetrical axis, but wobbled a little in the air. This means that the side it was initially thrown on is “up” for a little longer.

Coin tosses are still appropriate for everyday decisions. About one percent distortion is achieved in just a few throws Pretty accurate. If you still want to be 100% fair, you should hide the initial position of the coin before tossing it. However, if you flip a coin in your friend group, you can pay attention to which side is on top at first and pick one One percent advantage supply.