IS ARMAGEDDON CHESS FAIR? The asymmetry in the Armageddon rules raises the question of fairness. (A football fan might remember the discussion of how much of an advantage it was for a National Football League team in the old days to win the coin flip for possession when a game went into overtime.)
The Armageddon rules demonstrate the critical importance of time pressure in championship chess. As an example, apparently Karjakin was usually in more time trouble than Carlsen, and the shortage of time—especially in the last game—is thought to have led to his defeat.
Here is a discussion of the advantages of playing the black pieces in Armageddon.
I agree with this comment from GeneM: “Armageddon Chess is a fair tie-break system only if the two players bid for how much time Black should have.”