Mariah Carey and Jay-Z albums clash?

Mariah's "Memoirs of an Imperfect Angel" is set for a release date on the 15th of September, As Jay-z's "Blueprint 3" is set for a release date on the 11th of September, Usually albums are released on mondays but it seems that both album sales will be aculated in the same week. Who will debut at number one? Jay-z has had 10 number one albums, Mariah has had 6 number one albums, Mariah clearly has had more success overall. Will Jay-z's album sales will count from the 8th of september or will it be bumped with Mariah's album?. Jay-z's D.O.A peaked at #24 on hot 100, mariah's obsessed peaked at 11#