Coin Tosses Are Not 50/50

I just came across an article that says the results of a coin toss are not 50 percent heads, 50 percent tails as previously thought but instead does contain a slight bias.  Can you imagine that?  Apparently, someone ran an experiment in which they had 48 people toss the coins from 46 different currencies and the results they got were quite interesting.  This particular paper has not been peer reviewed but it is quite interesting none the less.

The man who lead the study believed that the reason for the bias has to do with the way the coin moves in the air when flipped.  He proposed that the side that is up when flipped is more likely to spin in the air with that side up so it has a better chance of showing when landing.

They concluded that if you look at the side that is up before you flip the coin, that is the side you should call.  According to their results, this strategy resulted in the correct call 50.8% of the time based on over 350,000 flips.  

For the study they used a specific method for flipping the coins.  Participants were to flip the coin with their thumbs and catch it in their hands.  If it landed on the table, it was not counted because the table added the possibility of a bounce, or a spin.  At one point they had people flipping coins for several days of 12 hour sessions to get enough flips for their study.

This study was inspired by a mathematician who was also a magician who said there was a slight wobble and an off axis tilt when someone flipped a coin with their thumb.  This observation was made back in 2007 and the researchers who ran this study proposed that the coins would land on the side facing upwards about 51% of the time.  

It was also found that the individual flippers results varied a bit because some managed to flip with almost no tilt or wobble while others had enough of a tilt or wobble to end up with the 50.8% result.  Further more, the coins nationality seemed to make no difference in the results.

Knowing this could help the person choosing the result to have a slight advantage in calling for who goes first in a sports game, who wins a mayoral election in the Philippines, or any other event that relies on a coin toss. If you were to gamble on the results of a coin toss, using this information could help you win money.  The solution to countering the bias is to not let anyone see which side of the coin is up before flipping it.

I found this interesting.  Let me know what you think, I'd love to hear.  Have a great day.