@psephomancy said in GPT and I invented a new voting system metric?:
@toby-pereira said in GPT and I invented a new voting system metric?:
I think if a measure isn't cloneproof it's probably not a good measure.
Why would that matter for a measure?
Because you can have a candidate that is the closest to being the Condorcet winner but not the Copeland winner. E.g.
14: A>B>C
4: B>C>A
12: C>A>B
A>B - 26:4
B>C - 18:12
C>A - 16:14
A has the biggest winning margin and smallest defeat, and is the nearest to a Condorcet winner by any reasonable measure. But then you can clone C and have a C1 and C2 but where C1 is always ranked above C2.
In this case A now has two defeats (against C1 and C2) so loses to both B and C1 in Copeland. But A is still the nearest to a Condorcet winner in terms of defeat sizes, so I would say they are still the "most Condorcet" winner.
