I advanced to TL playing coin games as well.
In any event, I only piped in to express and observation, kinda a de ja vu moment actually...
It seems that many topics are discussed over, and over, and over again in the forum threads but they have been going on so long, people forget. I went through another thread "Average Required For Tour Champion" and found some interesting points (from April, 2020), specifically one by Robert1893 on April 23, 2020 @ 7:33 am (posted time)(Page 12 of the thread).
https://www.wgt.com/forums/p/387781/4263127.aspx
This is what I garnered from his post:
"We use an algorithm to determine when a player is eligible to move to a
new tier, which takes into account a number of factors including number
of ranked games played....Additionally, in response to WGT player feedback about sandbagging.... WGT is using more than just ranked
stroke play scores to determine each player's average score and
appropriate tier ranking.... WGT is not sharing exact details of these
changes, but they include factoring in scores from players who perform
well in tournaments and challenge games for credits"
I also remember reading in a thread that WGT ultimately decides when a member "may" advance to TC....it appeared there was not specific criteria to do so but more of an Honor bestowed...(whatever)...I imagine it is similar to how one is promoted to "Hall of Fame" (which there is a thread all about that as well). It seems TC and above is decided by WGT taking into consideration a variety of factors, none of which may have to do with actually having any lower average than a Champ...imho
Mythanatos: only playing coin rooms. what the algorithm is who knows.
In another thread, from years ago, in discussing the mobile app, WGT_Champion had stated that, (on discussing the app), which coins rooms and matches are pretty much the same as what we are playing now, (my words not his)..WGT has specific levels that will push the player to the next tier. What those levels were, he did not say.
If interested, his post can be found here:
https://www.wgt.com/forums/p/531116/3605103.aspx#3605103