Yeah, more than likely a lucky medalian.... maybe a commerative coin from some past event.
If it is a regular coin, I would think it would be something that their kid gave to them for luck or anything that is special.
I doubt any of them use a run-of-the-mill quarter.
I only play a few times a year and I use the same coin. I have a dime in my golf bag that has been there for 15 years. That was my pop’s golf bag before he passed and that dime was in there when he used it. It is a special dime.
BUMP
That is what I figured.