Useful info:
in summary we have:
- When your average score is equal or smaller than 100 you go from hack to amateur.
- When it is equal or smaller than 80 you go from amateur to pro.
- When it is equal or smaller than 72 you go from pro to tour pro
- When it is equal or smaller than 67 you go from tour pro to Master
- When it is equal or smaller than 63 you go from Master to Tour master
- When it is equal or smaller than 61 you go from Tour master to legend
and
- you need to play at least 5 ranked rounds as hack before reaching Amateur
- you need to play at least 10 ranked rounds as amateur before reaching Pro
- you need to play at least 20 ranked rounds as Pro before reaching Tour pro
- you need to play at least 25 ranked rounds as Tour pro before reaching Master
- you need to play at least 40 ranked rounds as Master before reaching Tour Master
- you need to play at least 50 ranked rounds as Tour Master before reaching Legend
Notice that those minimal number of ranked rounds are also the number of best rounds used to compute your average in that particular tier. So if you are Tour Master for example, your average is computed with your best 50 ranked round (that's why you need at least 50 rounds to move up).
A couple things you should all know. One is that your average starts over after you reach a new tier. Your first round at the new tier will be your new average. Second, the rounds you need to complete as listed above are the number of rounds that you need in that tier. Not total overall. For example, you have to have 25 rounds and an average under 67 in the Pro Tour tier to advance to master.