Fig. 2

Ciruvis diagrams of combinations from the rules of H3N2 models. Models having at least three combinations are shown. The outer circle shows the positions. The inner circle shows the position or positions to which the position of the outer circle is connected. The edges show these connections. The width and color of the edges are related to the connection score (low = yellow and thin, high = red and thick). The width of an outer position is the sum of all connections to it, scaled so that all positions together cover the whole circle [26]