I'm sorry. I told you I didn't understand it. You probably think I'm really stupid, but I'm only used to betting on horses to win, not lose.

What I'm trying to work out is this. Using the example Duritz made, if you bet $100 on the horse to win at $3.50, you get $350 if it wins. That's easy. But I still don't know how to work out the 'laying' part of it. How much money do you bet and wouldn't you have to pay $350 if the horse wins? That's what I meant by paying extra money.