In this market SportingIndex predict how a player will perform in relation to a selected number of his/her competitors (usually 10).
It is important to note that only these 10 players count for the bet. As a result your selected player does not necessarily need to win the tournament for your bet to pay out.
In their Tournament Index points are awarded as follows: First of the 10 named players = 50 points, 2nd = 30, 3rd = 20, 4th = 10 and all others = 0.
Here is an illustration. In a typical US Tour Tournament, their quote for Phil Mickelson's might be 14-16 in a competitive 10-man index. If you believe that Mickelson would beat the other nine men in the Index, you would buy (go high) at 16 for the stake of your choice, in this case say £5.
If your assessment had proved correct and Mickelson finished top of the ten named players, you would have won 34 times your stake, in this case £5 per point: (50 - 16) x your stake = 34 x £5 = £170 . However, if Mickelson had finished 5th or lower of the 10 named players, he would not have been awarded any points so the same bet would have lost you 16 times your stake: (0 - 16) x your stake = -16 x £5 = -£80.