I found this in here:
When you have played 5 ranked rounds as Hack and achieve an average of 100.00 or lower, you are promoted to Amateur.
When you have played 10 ranked rounds as Amateur and achieve an average of 80.00 or lower, you are promoted to Pro.
When you have played 20 ranked rounds as Pro and achieve an average of 72.00 or lower, you are promoted to Tour Pro.
When you have played 25 ranked rounds as Tour Pro and achieve an average of 67.00 or lower, you are promoted to Master.
When you have played 40 ranked rounds as Master and achieve an average of 63.00 or lower, you are promoted to Tour Master.
When you have played 50 ranked rounds as Tour Master and achieve an average of 61.00 or lower, you are promoted to Legend.
When you have played 500 ranked rounds as Legend and achieve an average of 60.00 or lower, you are promoted to Tour Legend.
Ranked rounds are rounds played through stroke play not ctth, blitz or match play.
You can lower your average in match play if you win against a higher tiered player though up until you hit Legend.