Fair coins tend to land on the same side they started (arxiv.org)

Article summary

A study collected 350,757 coin flips to test the prediction that fair coins tend to land on the same side they started, finding a 51% probability of this outcome. The data supported this prediction, with a 50.8% probability of the coin landing on the same side. The study also found variation in the degree of this bias between individuals. The results have implications for understanding the physics and statistics of coin flipping.

Main themes

• coin flipping
• probability and statistics
• physics of coin motion
• betting and game theory
• human factors and technique
• experimental design and methodology

What commenters say

• The same-side bias in coin flipping can be exploited to gain a small advantage in betting, but it would require a large number of flips to be profitable.
• The bias may be due to the way people flip coins, with factors such as height and spin influencing the outcome.
• Allowing the coin to land and bounce on a hard surface may eliminate the bias.
• The study's findings are interesting but have limited practical applications, and the time and effort required to exploit the bias would not be worthwhile.
• The bias may vary depending on the individual flipping the coin and their technique.
• The use of high-speed video or other methods to analyze the coin's motion could provide further insights into the causes of the bias.
• The study's results are consistent with previous research on the physics of coin flipping, which suggests that the motion of the coin is not truly random.
• Some commenters have suggested that the bias could be used to develop a strategy for winning at games of chance, but others have pointed out the difficulties and limitations of such an approach.