Flipping the coin is not 50/50 chance?

[froment]

If someone is after enjoyable reading in these rainy days, I recommend this paper: http://comptop.stanford.edu/u/preprints/heads.pdf

  Quote

We prove that vigorously-flipped coins are biased to come up the same way they started. The amount of bias depends on a single parameter, the angle between the normal to the coin and the angular momentum vector.

It seems that beginning of the idea go back to 1986, and while further researching, I found some articles on this topic from 2002 and 2004; but this is first time I hear about this; quite stunning idea and approach, I loved it! :loon