| Saturday March 28th 2015


Subscribe by email:

We promise not to spam/sell you.

Search Amazon deals:

Coin-tosses aren’t fair

Many statistics examples start with “assuming a fair coin-toss…” But it turns out that coin-tosses aren’t fair; depending on your toss, there’s a small-to-alarming bias in the result.

1. If the coin is tossed and caught, it has about a 51% chance of landing on the same face it was launched. (If it starts out as heads, coin tossthere’s a 51% chance it will end as heads).2. If the coin is spun, rather than tossed, it can have a much-larger-than-50% chance of ending with the heavier side down. Spun coins can exhibit “huge bias” (some spun coins will fall tails-up 80% of the time).

3. If the coin is tossed and allowed to clatter to the floor, this probably adds randomness.

4. If the coin is tossed and allowed to clatter to the floor where it spins, as will sometimes happen, the above spinning bias probably comes into play…


Related Posts: On this day...

Leave a Reply

You must be logged in to post a comment.