Representation of the quartet-ranking principle. In the quartet-mapping triangle, each dot represents the relative support for the three unrooted topologies . The quartet-mapping triangle depicted here summarizes the support across all windows in the scanning procedure. The mean position for all quartets is indicated by and the maximum distance from the mean position is indicated by an arrow (d
). This example is based on the quartet with the highest d
in the 'pure' subtypes of the CRF03_AB data set (see Sequence data).