Originally Posted by d'Yquem

I absolutely get the combined nights. That makes sense.

But combined years doesn't (to me at least). Let's say in any given year, I did 50 nights with Starwood and another 75 with Marriott, so 125 nights, why should that count for two years, whereas for me, who does on average 125 nights on Starwood, would only get one year counted?

For the avoidance of doubt, I already have my 10 years+ of SPG Platinum and will hit 750 nights with SPG by the end of 2018 (not taking into consideration my 100+ Marriott nights) so it doesn't affect me.