Coin flips, which have long been believed to have an exact 50/50 chance, are actually slightly weighted towards one outcome, according to a study by European researchers. The study, released this week, revealed that the side of the coin that starts facing up has a 50.8% chance of landing in that same position.
The research team collected data from 48 individuals flipping coins from 46 different currencies and denominations, totaling 350,757 flips. Out of these flips, 50.8% of them landed on the side that was facing up at the beginning. This finding provides evidence that coin flips are not an entirely fair game.
A previous study conducted by American researchers in 2007 also found that coins were more likely, at around 51%, to land on the same side that had been facing up. The American study noted that factors like launch angle and wobbling influence the result of the flip.
The European researchers sought to test the counterintuitive results of the earlier study, which had a smaller sample size. They found variation among the 48 coin flippers, indicating that different individuals cause a varying degree of wobbliness in their coins.
When accounting for the starting side factor, the European study revealed that a flipped coin landed on heads 50% of the time and on tails the other 50% of the time. The researchers concluded that their data strongly suggests that when certain individuals flip a fair coin, it tends to land on the same side it started on, thus confirming the American study.
The lead author of the study, Frantisek Bartos, a psychological methods PhD candidate at the University of Amsterdam, pointed out that while the 50.8% odds may not be significant for small amounts of coin flipping, in larger samples, this advantage would be greater than the house edge in some casino games.
According to Mr. Bartos, if you were to bet a dollar on the outcome of a coin toss 1000 times, knowing the starting position of the coin toss would earn you an average of $19. This is more than the casino advantage for blackjack against an optimal player, but less than that for single-zero roulette.
Perspective: Although it may come as a surprise, coin flips are not as fair as once thought. The slight bias towards the side that starts facing up can be attributed to factors like launch angle and wobbling. While the difference may seem trivial in a small number of flips, it can become significant when large samples are considered. This interesting finding sheds light on the physics of coin flips and challenges the notion of a true 50/50 chance.
