This was posted in another thread, how accurate it is, I do not know. Well, I know that the Tour Pro is correct as it worked for me. Hope this helps.
Pro = average 80 with at least 10 ranked rounds played as Amateur
Tour pro = average 72 with at least 20 ranked rounds played as Pro
Master = average 67 with at least 25 ranked games played as Tour pro
Tour Master = average 63 with at least 40 ranked games played as Master
Legends = average 61 with at least 50 ranked games played as Tour