- Marty: "The future, that's where you're going?"
- Doc: "That's right, twenty-five years into the future. I've always dreamed of seeing the future, looking beyond my years, seeing the progress of mankind. I'll also be able to see who wins the next twenty-five World Series."
- — Before the arrival of the Libyans
At the Twin Pines Mall, before planning to go from 1985 to 2010, Doc Brown was looking forward to finding out who would win "the next twenty-five World Series". The Doc Brown from the "Lone Pine Mall" timeline, on the other hand, would say that he didn't invent the time machine to win at gambling, and stopped Marty from buying Grays Sports Almanac, which would have told both of them who won the World Series from 1985 to 2000.
On October 21, 2015, the Chicago Cubs won the series in a sweep over Miami, meaning that the Cubs won all the games. According to USA Today the next day, the win came in Game 5 of the Series. Sometime prior to 2015, the contest had gone from a "best of seven" to a "best of nine" format.
During his visit to 2015, Marty happened to see a news report of the World Series on a holobillboard. After overhearing an old man wishing he could have bet on the Cubs at the beginning of the baseball season when they had a 1 in 100 chance of winning, Marty was inspired to purchase a sports almanac in order to avoid becoming a "loser".
Behind the scenes
- During the weekend of October 26 and October 27, 1985, while Marty and Doc were traveling through time, the Kansas City Royals won Game 6 and Game 7 of the World Series, respectively, defeating the St. Louis Cardinals to win the Major League Baseball championship. The series was tied, at three games apiece, prior to the 7th game played on the night of October 27, hours after Marty and Jennifer said goodbye to the Brown family.
- In Part I, Doc Brown said "I'll also be able to see who wins the next twenty-five World Series." The winner of the 2010 World Series was the San Francisco Giants, defeating the Texas Rangers 4 games to 1.
- In the original timeline, Doc planned to see who would win the next 25 World Series. After the timeline was altered, Doc made plans to go 30 years ahead rather than 25, and stopped Marty's attempt to learn the results of future sports scores. Grays Sports Almanac would have included the results of the 1985-2000 Series, as well as other sports results. The film leaves open the question of whether Marty has learned any scores from briefly flipping through the almanac.
- In the novelization, Doc mentions that he is a fan of the "Brooklyn Bums", a nickname for the Brooklyn Dodgers. Marty says that he's a fan of the San Diego Padres. In 1955, Brooklyn won the World Series one month before Marty's arrival. The Padres had played in their first World Series in 1984.
- One of the jokes in Part II was that the Cubs would finally win the World Series. The Chicago Cubs last appeared in the World Series in 1945, and has not won the Series since 1908. Over the years, the Cubs have been famous for having many chances to win the National League pennant, but falling short in each instance.
- In real life, on October 21, 2015, the New York Mets swept the Cubs out of a chance to go to the World Series, and on November 1, Kansas City defeated Mets to win the World Series for the second time.
- The Kirk Gibson Jr. Slugger 2000 adjustable bat was mentioned in Part II as well. At the time the script was being written by Bob Gale in 1988, Kirk Gibson (Senior) had been the hero of the 1988 World Series. As Gale notes in the commentary, Gibson is not as well remembered now as he had been when the film was released. As of 2011, Gibson is the manager of the Arizona Diamondbacks.
- Miami did not have a Major League Baseball team at the time of the filming of Part II, and Marty was genuinely surprised to see a Miami team. The Florida Marlins team began play in Miami in 1993, and won the World Series in 1997. Soon afterward, an urban legend arose that Back to the Future Part II had "predicted" that a team from Miami would win the World Series in 1997. According to the news, of course, the Miami team will lose the 2015 Series.
- In 2012, the Florida Marlins changed their name to the Miami Marlins. However, barring a league realignment, it would be an impossibility for the Chicago Cubs and Miami to face each other in the World Series, as they are both National League teams. In 2015, there was no realignment, so this prediction did not come to pass.
- Bob Gale, a fan of the Cubs interdivisional rival St. Louis Cardinals, stated that the Part II joke was done because the World Series is the most important sports event in October.