[EM] Markus: You still haven't defined "prefer". So your criteria remain undefined.

[Markus Schulze]

Dear Mike,

an election method is a mapping from a given input to a
given output. Where this input comes from or what this
input actually represents is of no concern as long
as it has the properties required by this election
method.

For example, a partial ranking of the candidates
A, B, C, ... has the following six properties:

a. For each pair of candidates A and B exactly one of the
   following three statements is true: A = B, A > B, B > A.
b. A = A is true for every candidate A.
c. (A > B and B > C) => A > C.
d. (A = B and B > C) => A > C.
e. (A > B and B = C) => A > C.
f. (A = B and B = C) => A = C.

What a "candidate" is or what ">" or "=" means is of no
concern as long as the above six properties are met.

For example, the "candidates" can be sorts of apples and
">" can mean "is sweeter than".

Markus Schulze