SPG had a published definition for qualifying years which made it clear challenge years did not count. Marriott had no definition and when they used to require a minimum number of years for status they included challenge years. For Marriott to suddenly change its rule or apply SPG rules to years there wasn't even a hint of merger would seem unfair, so it is understandable they would follow the rules as they were and not count challenge years on the SPG side while counting them on the MR side. Might I have done it differently? Probably. But the way they are doing it has some basis and fairness.