Coin Flips

[hippiechic]

What is the official ruling on coin flips? When I flip the coin into the air and I call heads or tails, upon catching it do I have to put it on the table palm down, or is it simply caught in my hand palm up, or can I choose which way I prefer to do it? With Krark's Thumb on the table am I allowed to flip both coins simultaneously? If me and my opponent both are required to flip with me having a thumb out, do we both flip once, then I flip again, then I choose which I want to keep? What are the rules concerning excessive coin flips with the intention of running down the game clock?

[Clariax]

There's no official ruling on how to flip a coin. Just reach an agreement with your opponent on a method that is 50/50 and random.

Doing anything excessively just to run out the clock would likely fall under stalling.

[BC]

I've never actually seen anyone ever flip a coin in a tournament.  Pretty much everyone just rolls dice (even/odd).