[Leo_The_Lip]

I've been making fictional leagues since the days of Season Ticket Baseball and many of the settings I use are described above. However the best way of ensuring you have meaningful rivals has not been mentioned, and it is simple.

Allow randomness to consistently challenge you.

A 4 x 8 league of 32 teams pretty much ensures that at least one of the 31 other teams in any given season will be a solid challenge for you to take on. It will likely be a different team each season, but there will be hefty stumbling blocks every year.

Also, in the 4 x 8 only allow the top two in each division make the playoffs. You can' 'get hot in the playoffs' if you don't make the playoffs with an 85-77 team.