Physically, I know there is no difference flipping a nickel.
It may seem like in my mind that a nickel is heavier (obviously only slightly) on heads because of the raised head on the coin.
Btw, I ALWAYS call tails.
Even when my opponent flips and it's a nickel, I still call tails out of stubbornness and preferences to always choose "tails."
In my mind, I think it will be heads anyway because of what I said above.
But, all coins are equal when flipping. One side isn't heavier than the other.
I know this because I searched the web for any website or research that could tell me otherwise. I didn't find anything.
But I thought it was cool when my Friday morning opponent dug for a coin in her purse for us. She found a coin and then asked me, "is it okay it's a nickel?"
Made me wonder why she asked me that.
Still curious. If I see her today during the team event I will ask her. Makes me wonder if she feels the same about nickels, lol.
Update: She said she asked if the nickel was okay because she was new to this tournament and pool, and didn't know if we had to use a certain coin or not.