Originally Posted by
tb21nym
I stayed over 100 nights this last year between Starwood and Marriott. I was just demoted to Gold in both programs because I barely missed the threshold in each program.
It seems it would take real effort to stay "over 100 nights" across the two separate programs in 2017, and not achieve Platinum status in either one of them.
For SPG Platinum, you only needed 25 Eligible Stays or 50 Eligible Nights.
You indicated you had a Marriott Chase Visa (which provides 15 elite-qualifying nights, plus another for each $3000 spent on the card), So, you would have needed no more than 60 nights for Rewards Platinum.
With more than 100 nights, all it would have taken is a bit more attention to the qualification rules and picking a few hotels more carefully in 2017.