 Every reform of an imperfect practice or institution is likely to be unfair to someone …To change the rules in the middle of the game, even when those rules were not altogether fair, will disappoint the honest expectations of those whose prior commitments and life plans were made in genuine reliance on the…old rules. The propriety of changing the rules in a given case depends upon (inter alia) the degree of unfairness of the old rules and the extent and degree of the reliance placed upon them…we must weigh quite legitimate incompatible claims against each other in circumstances such that whichever judgment is reached it will be unfair to someone or other (Feinberg 1973: 268). 