Some quite in-depth responses! I have enjoyed reading them but there is still a lot of emphasis on the idea of counties playing cricket, but that directly feeds off the private/familial and grammar school system, which has stifled the game. So much talent is lost from comprehensive schools, working class backgrounds, South Asian cricketers plying their trades in random clubs or just playing recreational cricket on the odd weekend.
The ECB claimed, years ago that they wanted to access and promote such communities but each initiative has been either a failure or a PR stunt...or both.
So let's imagine an honest ECB and a genuine blank slate.
Cricket teams, playing a 4-day championship should be region based, some regions could be entire cities, London, Birmingham, Manchester come to mind and others could be geographical regions, combining towns and cities. How many teams this would generate obviously requires a deeper dive but I'd be looking at say 8-10:
London
Birmingham
Manchester
South West England
Mid-East England (Norwich, Colchester etc)
North England
East Wales (Cardiff and additional districts)
West Wales (Swansea and additional districts)
That is just off the top of my head but all areas contain metropolitan centers as well as access to grammar and private schools, with local grounds if international grounds are busy.
Each team plays each other twice: home and away, making use of out grounds if needed.
Obviously all of this requires a revamping of the financial structure, where private investors essentially create IPL/PSL/Hundred style franchises. Team sports the world over has shown that there is loyalty of city/regional based teams with lots of sponsors willing to work with such outfits.
There would need to be investment in local grounds and parks, in comprehensive schools and competitive junior level cricket, with academies feeding into each of the teams (much like PL football academies all across the country).
The aim would be to play games during the best summer months of June, July and August:
Games to be separated into round 1 (all teams play each other once) - June
Round 2 (teams playing each other the second time around) - late July through mid-August
Obviously the home test summer would be played throughout this period too, but the use of out grounds would help, as would smaller, locality based arenas that could hold a few hundred spectators. When there is no home test/LO cricket, all England players must be available for their counties if they have had a max two-day break.
It's a basic structure with a lot of detail to be worked out but my aim would be to maximise interest in the game, provide the best quality weather and games, while appealing to a much wider audience.