The reason [Marty] sets the DeLorean to Oct. 21, 2015? It’s the day 30 years in the future when the Cubs are predicted to win the World Series. Bob Gale, who scripted the 1985 original with Robert Zemeckis, said that he tried to figure out when the final game of the Series would have played: “I did my homework as a baseball fan.”
“Marty McFly Returns! : snopes.com [1]”
But the Cubs [2] are down three games [3] and we still don't have hover boards [4].
Sigh.
[1] http://www.snopes.com/2015/10/20/marty-mcfly-returns-2015/
[2] http://chicago.cubs.mlb.com/
[3] http://www.cbssports.com/mlb/eye-on-