If two people have the same score, then the person with the higher tiebreak score will be ranked higher. The tiebreak score is calculated using the Neustadtl score system, which is explained here: http://en.wikipedia.org/wiki/Sonneborn-Berger_system
Basically, you take the sum of the scores of the people you beat, plus half the sum of the people you drew against to calculate your tiebreak score.
I am in a tournament and wondering how points are calculated. A guy with the same score as me has more points, can someone shed some light on the subject please?