How random is a coin toss?

Alex Bellos discusses how the Incans used knots in string (Quipu) to record numbers.Check out Brilliant (get 20% off their premium service): https://brillian...

Randomness, coins and dental floss!
Featuring Professor Persi Diaconis from Stanford University.

To catch or not to catch: http://youtu.be/Obg7JPd6cmw
Extra footage (Numberphile2): http://youtu.be/9RKKoXw7wJw
Superbowl coin tosses: http://youtu.be/bFfSfzjhfC8

Paper shown in this video (Dynamical Bias in the Coin Toss): http://bit.ly/DynamicalBias