Best Fielding in Cricket History - Top Cricket Fieldings - Cricket Highlights 2016
If the premier division consists of eight teams, nothing much changes from the current schedule; if it consists of six, then Sri Lanka or West Indies might give up on Test cricket, thinking it too long a haul to reach the top again, and their players would focus ever more on white-ball cricket not just their own domestic leagues but the Indian Premier League.
A premier division of seven teams, playing in a three-year cycle, with home and away series of three Tests (or five for the Ashes), should achieve the right balance. No team could afford a serious lapse, and the country who are relegated can expect to be promoted again in three years. Or it might be saved from relegation by winning a play-off against the second division winners.
This second division would consist of five teams: initially Bangladesh, Zimbabwe, Afghanistan, Ireland, and the team that will be eighth in the ICC rankings at the cut-off point. They would not play so often in the three-year cycle, but then the broadcasters would not want them to. And there is scope for other countries to join, like Nepal.
Source: http://www.telegraph.co.uk/cricket/2016/06/04/sorry-sri-lanka-highlight-the-need-for-two-divisions-in-test-cri/