I am sort of confused by IHG rollover nights. I'm at 36 nights for the year currently and debating whether to bother getting 40+. I already have club benefit for next year. I have Diamond status expiring at the end of the year and also platinum status from credit card.

If I get upto 39 nights, will I have 19 nights roll over to next year? And will those 19 nights count toward tier awards? I'm thinking 19 rollover nights might be more valuable than the suite upgrades / club benefit (since I already have it). If I can start 19 nights then that makes Diamond re-qualifying next year a lot more doable.