That's because, just like the PGA, there can only be one winner.
WGT has a series of tie breaker rules in the event of a first place tie.
* Best score over the last 6 holes
* Best score over the last 3 holes.
* If there is still no winner, then scores are compared on a hole by hole basis from the last hole to the first.
* In the unlikely event that a tie still remains, then the first player to post his/her score will be declared the winner.