For events where biased fractionation is detected, these confidences include assigning each gene to a subgenome, and confidence values range from 0.0-1.0.
For events without biased fractionation (here the Yeast WGD), the orthology assignments are degenerate with respect to subgenomes, meaning that the assignment 000..0-111..1 and 111..1-000.0 are equivilent. As such, potential confidence values range from 0.0-0.5, and the picklist is populated accordingly.