@freemo hmmm.. you're making good points. I think it is a bit of a sinkhole that if you get stuck with two major parties it's hard to get away from that.
The math argument bothers me, where: if A is the least attractive but major, B is moderately attractive and major, C is most attractive bit minor. If you vote for B, you have reasonable chance, but if you vote for C and lose, then your vote that otherwise would've gone to B is now lost, therefore directly benefiting A.