Script for existing PHP game

I have made a PHP racing game, it is near completion but one area is slightly out of reach of my skills. I need players to be able to join and race each other, it then decides from some database figures (their cars kit, the track and the damage of their car) who wins. Resulting in them getting prizes and displaying a results page. > 2, 4, 6 and 8 player vs player races > Races are listed in a table so you can see which have finished, when they start, which to join > Results for the race with some basic stats > Dispense a win notification and game-money to winners (2 players, only 1st gets winnings, 6 players, 1st, 2nd and 3rd get prizes etc) > Updates their kit with how much wear they have received I have already done all this (twice, hehe) but it never really works (I wanted to use the same system to do a tree knock-out tournament system too!)... So there is a brilliant example already in place for you to get a very good example from.