You flip/toss a coin in the air, then:
let it fall to the ground/table/surface and come to a stop, then call it however it fell.
catch, then reveal.
catch, flip it onto the back of your other hand or a table/surface, then reveal.
some other way.
I didn’t vote because I never toss a coin. I once heard a lecture by a magician turned mathematician whose main point was that it is essentially impossible to toss a coin fairly. And it is easy to learn how to toss a coin in such a way that it wobbles, but never turns over and even he, an experienced magician, cannot detect it.
Some other way. “Who’s going to Dewey today?” “lets toss a coin!” tosses coin, fails to catch it, scampers around to see what is showing and then ask “ummmmmm, its heads…what does that mean?”
Most of my major decisions are made with my magic 8 ball.
Hari Seldon: I can easily accept that it is possible to throw a coin unfairly – but why should it be impossible to throw one fairly? Just give it a hefty flip with the thumb so that it rotates in the air seven or eight times…and… Well, that’s the point: did it flip seven times, or eight? I don’t see why it would necessarily favor one over the other. What possible intrinsic bias would there be toward (or against) an even number of flips, as compared to an odd number of flips?
(Especially since my placing it on my thumb, before flipping it, is, itself, essentially random! I would never make a practice of putting it there in one specific orientation every single time.)
I haven’t tossed a coin in a very long time, but I prefer to spin a quarter on the tabletop and let it fall. There can be no accusations of bias when you spin a coin, as opposed to flipping it.
That’s why you declare how you’re goin to do the catch/drop/turn over/whatever and then the other person calls it in the air.
“I will catch it and turn it onto the back of my hand, you call it in the air.” Even if you can force it so you can catch it in your hand with tails up, can you force the other person to call tails?
Except that of the natural weighted bias of the coin. They are far more likely to end heavy side down when spun.
My preference when coin tossing is to flip, catch, turn onto hand. Sometimes (like when refereeing) I go with the “fall to the ground and reflip if needed” way as that’s how it’s done in my area.
That letting it fall on the ground business is bad form. Catch it, slap on the back of your hand, reveal.
I said “some other way” because my answer is really “it depends.”
When I’m officiating a ball game and I have to flip a coin; there’s only one acceptable way to do it. You flip it into the air and let it fall to the ground. If I’m flipping for “even or odds”** then I flip it, catch it, and slap it onto my other forearm until the other person is ready to reveal.
**even or odds is a game where you bet a quarter. Two people flip a coin simultaneously, and one of them says “even” or “odd.” If the two coins match, it’s even, if the two coins don’t match it’s odd. It’s a great way to pass the time. 