For all major rugby union events (Guinness Premiership, Six Nations, World Cup, etc.) SportingIndex offer a market based on how individual teams will perform.
Points are awarded to the teams who finish the event in the top positions. For example, in the Six Nations Championship, SportingIndex might award 60 points for the team who topped the final table, 40 points for the team which finishes second, 20 points for third, 10 points for 4th and 0 points for the others. This gives you the opportunity to predict not only how well a team will perform, but how badly they may do as well.
Let's look at an illustration. During a Six Nations Championship, SportingIndex might reckon that England are favourites to win, this would be reflected in their prediction of 36-39 points (based on the points system outlined above). If you believed England are going to be pretty much unbeatable, you would place your spread bet high at 39, say for £5 per point.
Had England ended up winning the Six Nations you would have won 21 times your stake: (60 - 39) x your stake = 21 x £5 = £105. Even if they had slipped up and finished second, you still would have made 1 times your stake: (40 - 39) x your stake = 1 x £5 = £5.
However, if England finished third you would have lost 19 times your stake as they are awarded 20 points: (20 - 39) x your stake = -19 x £5 = -£95.