Is a Coin Flip Fair? The Math Behind the Coin
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Heads or tails is the oldest draw there is, and its reputation is of perfect fairness. With an honest coin, each side has a 50 percent chance. Yet a real coin has small deviations.
Physics studies of coin tossing show that a coin flipped in the air tends to land on the same side it started on slightly more than half the time, because the spin is not always perfect. The difference is small, but it exists, and it depends on how each person flips. Also, with practice, a person can influence the outcome.
Another problem is proof. If the coin lands out of sight, nobody can confirm the side. In disputes, the word of the person who flipped counts for more than it should.
The digital coin trades those flaws for other controls. The side comes from a random seed generated on the server, not from a human gesture. Each side has the same chance, and the result is stored on the result link, together with the seed. Anyone can use the verification to redo the flip and confirm the side.
A common-sense tip: agree who takes each side before flipping. Choosing after the flip cancels the idea of chance.
To settle something simple right now, flip the coin and share the link.