Funny that Kentucky might end up with one of the fairest maps (from a partisanship standpoint)
From a *purely partisanship perspective*, 5-1 is actually not fair at all. Biden won 36% of the vote in KY, so he should win a comparable number of seats, which would mean 4-2 is the fairest partisan outcome.
"Fair" in the context of FPP does not mean proportional. FPP is just not a system that can accommodate proportionality, and trying to force proportionality into it results in nonsensical monstrosities.
I agree, which the second part of my post (which you conveniently didn't quote) made very clear. What does fair, purely from the perspective of partisanship, mean, if not proportionality? A 5-1 in KY is fair because it makes sense given other dimensions like compactness, COI, etc. Drawing a 4-2 in KY (and one of the 2 would still be quite competitive) would require nasty, nasty lines.
That's a complex question and one that can have many dimensions depending on how far you want to take it. The most obvious requirement for partisan fairness is pretty obvious though: the partisanship median seat must match the partisanship of the whole polity. Of course, with regard to congress, that only makes sense when analyzing the national map as a whole - how the median seat in Kentucky votes has little relevance on partisan fairness. That said, it ought to be possible to develop some kind of algorithm to measure whether a given state is skewing the national median one way or the other.
