Gray's Sports Almanac.v. to sportsalmanac, sportsalmanacking, sportsalmanacked
gerund, in a time-travel story or gaming scenario, the act of using future information to change the past for evil, usu. selfish purposes; from sports almanac; see addendum. Ex: I was the one who found Napoleon’s gold. Then Harris went through the Rift to ten minutes before I got there, and totally sportsalmanacked me!

Addendum: In the science-fiction comedy Back to the Future Part II (1989), when Marty McFly is in the year 2015, he purchases a book called Grays Sports Almanac, which contains sports scores for the years 1950 to 2000. When Marty returns to 1985, he intends to use the almanac to win in sports betting. Doctor Emmett “Doc” Brown discovers Marty’s intentions, and discards the almanac. The almanac is discovered by the 2015 version of Biff Tannen, who now understands that Doc’s DeLorean is a time machine. Biff steals the DeLorean and travels back to 1955, and gives the almanac to his younger self. The younger Biff uses the information in the almanac to become a Koch brother, transforming Hill Valley in 1985 into a dystopian hellscape.

In order for an action to be considered sportsalmanacking, the sportsalmanacker must have selfish intentions. Going back in time to kill baby Hitler, or baby Justin Bieber, is not sportsalmanacking, because one is trying to aid humankind. However, when Edmund Blackadder uses his time machine to become absolute monarch of Great Britain and to marry Maid Marian, that’s sportsalmanacking.