"We analyze the natural process of flipping a coin which is caught in the hand. We show that vigorously flipped coins tend to come up the same way they started. The limiting chance of coming up this way depends on a single parameter, the angle between the normal to the coin and the angular momentum vector. Measurements of this parameter based on high-speed photography are reported. For natural flips, the chance of coming up as started is about .51"

A new study using 350,757 coin flips proved an old theory that coin flips are not 50/50.  While minor, 51% can be a factor in sports and gambling with thousands of coin flips.

 

Dynamical Bias in the Coin Toss | SIAM Review

Edited October 13, 20231 yr by Uncrowned Guard

This was an interesting read! I can agree however on the 51% may not seem like a big deal but do it enough & the odds can be in another's favor. I didn't realize if you "vigorously" flipped it, they can land the way they started.

I wonder if sports and the like will change their coin flip rules?  What else could they use? I suppose they could just hide the starting side.