I remember spread betting was huge in the early 2000s in the UK. Bookies pick the line and you bet an amount. If you bet the over you win your stake multiplied by how much over it is, if the under comes up you lose your stake multiplied by how under it was. Overseas cricket pro used to spread bet on corners and time of first goal on EPL games.
Reckon this will be popular here? Looks more complicated than it really is on first look.