[thret]

This is a trick that can be learnt with practice. If you spend a lot of time around gamblers, don't ever accept a coin toss proposition.

[jahnu]

Doesn't the person not tossing the coin get to call though?

[letstryagain]

If you call tails, I catch the coin and show it to you. If you call heads, I'll catch the coin and invert it before showing it.

[jahnu]

Ahh right. People I know usually call after the flipper catches and covers it. So they would have to have some technique for flipping it as they raise their hand to reveal the coin. Difficult but I guess not impossible.