March 7, 2004
Beware the Coin Toss
It looks like it isn't quite fair:
The typical person flipping a coin varies enough in velocity, position, angle, and such to produce random-looking sequence. But when viewed this way, there is no reason for the flips to be precisely fair.And if Diaconis is flipping they will land the way he wants them 100% of the time.Now, with mathematician Richard Montgomery, Diaconis has shown that coin flips are in fact slightly biased to land on the same side as they started when flipped. By closely observing people flipping coins and carefully modeling the process, they estimate a bias on the order of 1�2%, dominating for example the house advantage in some casino games.
Via Marginal Revolution.
Posted by Steve on March 7, 2004Comments
If the toss is made in perfect double ignorance, things are still jake, though, yes? If you toss without showing me the starting position and I call it in the air, then neither of us can take advantage of the 1-2%. Aren't we back in 50-50 land, then?
Posted by Jim Henley at March 8, 2004 6:43 PM
