In the card game, Clay Strickland's first task is to alter the timeline to cause Emmett Brown to be murdered by Libyans in 1985, preventing his arrival in 1885. His second is to ensure Clara Clayton survives and that the ravine be named Eastwood Ravine. Then his third is to ensure the Biff Tannen of 2015 gives the almanac to his 1955 self, to ensure Emmett Brown gets committed. It's possible that Clay is a descendent of 1985A Mr. Strickland.