Martin (1992: 200):
Concessive conditionals can be further subclassified according to the universality of the contingency denied. Single, alternative and universal concessive contingency is illustrated below:
CONDITIONAL/CONCESSIVE: SINGLE[4:81] Even if we get that judge againwe'll win.
CONDITIONAL/CONCESSIVE: ALTERNATIVE[4:81] Whether we get that judge again or notwe'll win.
CONDITIONAL/CONCESSIVE: UNIVERSAL[4:81] Whichever judge we getwe'll win.
 Neither the 'alternative' nor the 'universal' agnate involves the logical relation of condition: concessive — if P then contrary to expectation Q. Both involve the logical relation of positive condition — if P then Q. Winning is not contrary to expectation under either condition.
 This confuses enhancement (condition) with extension (alternation). Here the logical relation of extension: alternation — X or Y — is realised in the clause nexus forming the condition (whether … or not).
 Therefore, the difference between the three conditionals is not "according to the universality of the contingency denied".