[jmount]

My small take: http://www.win-vector.com/blog/2015/04/i-still-think-you-can...

[plonh]

If the coin has a substantial thickness, is it still accepted as a coin? I think not. How much density differential do you need to generate a 1% bias in a coin no thicker than any existing UN member currency?

[jmount]

Persi Diaconis did a lot of experiments- the biases are very low.