Adele has that one on lock. Billboards tracking year is from November to November, so a big part of 25's sales will contribute to Adele's total points.
When will people realise that Streaming plays a MASSIVE factor in popularity these days. And not just with Rih. She should get praised for having high streaming numbers because it shows PEOPLE want to stream the album, whether it's Work or the album tracks. People need to stop trying to down-play Rihanna's success this era.