American betting odds

Can someone explain how the American betting system works please. Im in the uk and we use 10-1 or 7-2 etc

Is -200 good odds? I don't get it.

Cheers Phone Post

 -200 = favorite. means you have to bet $200 to win $100(plus you get your original stake back) 

+200 = underdog. means if you bet $100 you win $200 (plus you get your original stake back)

Cheers. Thanks. It's obvious now. Phone Post

 i hate our system :)

@DeanoBirko You found any American sites offering better odds than the UK sites? I've been shopping around and StanJames seems to have the best UK odds for 141 (11/8 for Lesnar, most other places are 5/6)