This method/strategy is rock solid! Thank you for this since me and a buddy got it in only 2 days (took around 7/8 hours). Much appreciated!!! We used 5 ghost accounts (instead of 7, so it goes a bit faster then mentioned above). Here are some stats from our run, hope it helps:
1st ghost-account: 37 games played, took 90 min., reached lvl 25
2nd ghost-account: 16 games played, took 35 min., reached lvl 35
3rd ghost-account: 26 games played, took 70 min., reached lvl 43
4th ghost-account: 24 games played, took 70 min., reached lvl 47
5th ghost-account: 30 games played, took 80 min., reached lvl 50
* With the 5th account we already achieved lvl 50 after 18 games played, but we did an additional 12 matches in order to cement this account more in place (meaning that with more games played the rankdrop would be less while boosting off from this account).
* Furthermore, when setting up a new account it's a good thing to boost off a bit from multiple accounts, e.g. with the 4th account we first played a match against the 1st account, continueing with a match or two against the 2nd account and finishing up with the remaining matches played against the highest-ranked account (in this example being the 3rd account).
* My own account was a bit shaken up to start with since I already played 17 matches (10 W, 7 L) in the early days while not being aware of screwing up my stats. So we went in expecting the worst. Nonetheless I got the G.O.A.T. in 44 matches (in 2 hours). My friend who had a 'clean' account got it in 10 matches (in 30 min.).
Good luck to you all! I'm 1 happy bunny