I think the ruling is that if say there are 3 teams on equal points then the team who has the most victories against the other two teams goes above them and the team with the least wins against the other two sides is last. If the teams have 1 win agianst each other each then NRR comes into it. So if for example, Kenya, Sri Lanka and New Zealand are level on points then Kenya will be on top of them because they won both their games against NZ and SL and NZ will be below Kenya and SL because they lost to both of them. I think this is how it works.