The bank ABSOLUTELY makes sure that the cheque is real and valid before they even bother looking to see if there's enough money registered to the account that it is drawn against.
I honestly assumed cheques were printed to be unique, making the piece of paper the proof in itself. I never used cheques in my life, so assumptions are all I have, sadly...
How do we designate an "official decider" that gets to choose which transaction actually IS first?
I get that first-come-first-served alone is just a beacon for frauds, but I still don't get how the mining makes it more secure (yes, I am that dense. Sorry...). I may need to watch the B3B1 video a few dozen more times....