# That Random Coin Toss? Not So Random Afterall...

### from the a-weaker-man-might-be-moved-to-reexamine-his-faith dept

One of my all-time favorite scenes in a play and movie, is the scene in Tom Stoppard's Rosencrantz & Guildenstern Are Dead where every coin toss comes up heads, leading to a bit of a philosophical discussion on probability. Of course, the randomness of the coin toss is the quintessential example of a random event and is used regularly for a variety of situations in which randomness is required, let alone expected. Except... it turns out the common wisdom may be wrong. Paul Kedrosky has the news of a test that showed that if you ask people to try flip a coin and get more heads than tails, they will, and not by a small margin either. In the test, 13 people were asked to flip a coin 300 times, trying to get as many heads as possible. All 13 participants got more heads than tails. Seven out of the thirteen had statistically significant margins of heads over tails (meaning almost certainly not a matter of chance). The highest was one individual had 68% of the coin flips land heads. In other words, a coin toss isn't particularly random.

Filed Under: coin toss, random

1. RD, 11 Dec 2009 @ 5:56pm

### Ok this is weird, but

I've known for a couple of decades now what the trick is to a coin toss. But you have to do it one certain way. If you do the "Traditional" coin toss, where you flip it with your thumb, catch it in palm of hand, then smack it over onto the back of your other hand, you can get better than 90% right. It will come up opposite (I think, its been a while) of whatever it was when it was facing up before the flip. Dont know why, it just does, if you flip-catch-slap it right. You can win a lot of bets with this method. Dont know if other methodologies work this way for coin tosses, but this one is consistent. Just dont EVER bet the farm when someone else flips, as they might not do it "right", always try to be the flipper yourself to control how it works.

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