Near as I can tell each game goes on sale 42 days before...but then there are memberships and loyalty points and maybe you should join the CIA (Chelsea in America), but it’s better if you join both and, and, and... I’m going to be in London for Matchday 4 (v. Sheffield) and would love to score a ticket.
I caved and bought a hospitality ticket. The whole CIA process was a little too involved for as often as I’m likely to be in London for a game. Stubhub had tix, but I also read it was expressly illegal to resell tix so didn’t feel comfortable chancing it. Stamford bound for CFC v. Sheffield.