Originally Posted by Scots_Al

You arrive at a stationary carousel. You can see where the bags will come onto the belt, but you don’t know which way the belt will turn... you have to pick a side before the hordes arrive! Get it wrong and you could be faced with the prospect of either an undignified chase after your bag, or a long wait watching it go all the way around before getting to you!

Originally Posted by fripperies

You just look at the belt. It's segmented with overlapping flaps. There is only direction it can logically travel. Think of how slates are laid on a roof and you'll get it.