The Grays Sports Almanac: Complete Sports Statistics 1950-2000, also known as Grays Sports Almanac, is a sports book that contain every sporting event in between years 1950 and 2000, that plays a big role in the sci-fi/comedy movie sequel Back to the Future Part II. The Almanac was used by old Biff, so he could alter the timeline, so his younger self can become rich and all-powerful.