An Abundance of Katherines Equation Grapher
If the graph looks more like a frown (goes up then down), then partner 1 will be the dumper.
If the graph looks more like a smile (goes down then up), then partner 2 will be the dumper.
The formula also argues that the steeper the curve, the shorter the relationship in question will be.
This was inspired by (read: shamelessly stolen from) John Green's book "An Abundance of Katherines". The equation was created by Brotherhood 2.0 resident mathematician and Illinois State Representative Daniel Biss, in conjunction with John Green.