I don't think there's any spoiler because most everyone has seen Back to the Future II or is at least familiar with the gist of the plot. Marty McFly (Michael J. Fox) buys a sports almanac in 2015 scheming to place some bets after he goes back to 1985. Doc Brown (Christopher Lloyd) discovers the book shortly after and throws it away. Old Biff Tannen (Tom Wilson) digs the almanac out of the trash and steals the time machine to give it to his younger 1955 self which creates an alternate 1985 in which Biff Tannen is rich.
Yes, that alternate timeline was a dystopia but it wasn't all bad. That timeline also has an episode of Lifestyles of the Rich and Famous featuring Biff Tannen giving Robin Leach an atomic wedgie. Funniest clip in the YouTube multiverse.
Just how wealthy was alternate 1985 Biff Tannen? Was he a billionaire or just a rich multi-millionaire?
The key to alternate 1985 Biff Tannen's wealth was his copy of Grays Sports Almanac: Complete Sports Statistics 1950-2000. As Old Biff told his younger counterpart:
You see this book? This book tells the future. Tells the results of every major sports event till the end of this century...
There is one caveat to that though. Biff Tannen didn't know due to his inexperience with time travel that those statistics in the sports almanac aren't guaranteed to be static. Print from the future such as a "YOU"RE FIRED!" fax, the headlines and text of a newspaper, or even photographs can be dynamically altered by changes in the timeline.
Consider the narration in the documentary display of the Biff Tannen museum. Keep in mind just like China propaganda the information is heavily biased:
Ladies and Gentlemen, welcome to the Biff Tannen Museum! Dedicated to Hill Valley's #1 Citizen. And America's greatest living folk hero. The one and only Biff Tannen. Of course, we've all heard the legend, but who is the man? Inside you will learn how Biff Tannen became one of the richest and most powerful men in America. Learn the amazing history of the Tannen family, starting with his great-grandfather, Buford 'Mad Dog' Tannen, fastest gun in the West. See Biff's humble beginnings and how a trip to the race track on his 21st Birthday made him a millionaire overnight. Share in the excitement of a fabulous winning streak that earned him the nickname "The Luckiest Man on Earth." Learn how Biff parlayed that lucky winning streak into the vast empire called Biffco. Discover how, in 1979, Biff successfully lobbied to legalize gambling and turned Hill Valley's dilapidated courthouse into a beautiful casino-hotel!
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A documentary Biff Tannen must have approved described Biff Tannen as one of the richest men in America. Why not the richest man in America? Why not the richest man in the world? I believe its because the sports almanac became a random variable. The more Biff used it to gamble the more the statistics in the book would change.
Let's try to construct the off-screen timeline of what happened to alternate Biff Tannen between 1955 and 1985.
Biff Tannen got the sports almanac in 1955. Biff Tannen couldn't legally place any bets until his 21st birthday. Between 1955 and 1958 Tannen would regularly compare sporting results with what was listed in the almanac and they would match perfectly. With 100 percent confidence Biff bet everything he had on a horse race in 1958 and became an instant millionaire.
After the 1958 horse race Tannen was seemingly on a winning streak. People started to notice and started to refer to Biff Tannen as "The Luckiest Man on Earth." I am sure at least a few bookies had a less flattering moniker for Biff.
What would happen if word got to the players of a team that "The Luckiest Man on Earth" bet on them to win? Might they be at least a little overconfident causing them to not perform as well as they would have?
The sports almanac lists sporting results up until the year 2000. What if someone who would have become a notable athlete in the original 1990s timeline had been killed by gang members in Biff Tannen's dystopian 1985?
Just by making successful bets Biff Tannen could cause changes to the timeline different from what was recorded by the almanac in the original timeline.
I'd postulate by around the mid-1960s at least once or twice after making a bet that would cause a change in the timeline the final score would have changed in the almanac. By this point Biff would have suspected the sports almanac was from the future and that the future could be changed. Realizing this Tannen founded BiffCo Enterprises to diversify and not rely so much on the sports almanac to build wealth. Maybe by the late 1970s almost every statistic in the sports almanac changed after Biff placed a bet. Perhaps Biff Tannen's Pleasure Paradise Casino was a way for Biff Tannen to gamble without gambling. Other people without knowledge from the future almanac would place bets creating less ripples in causality.
The problem with this hypothesis is that Biff Tannen doesn't seem particularly good at abductive reasoning. There is no indication from alternate 1985 Biff speaking to Marty that Tannen suspected the almanac was from the future. Alternate Biff seemed to just accept at face value that the almanac existed and had results from sporting events before the events occurred. Biff doesn't even mention the scores in the book changing.
Family members in a picture slowly faded from existence in the previous movie of the trilogy. Maybe all the scores that would have been skewed in Biff's alteration to his timeline after 1958 were slowly changed in the sports almanac between 1955 and 1958 to match the new timeline?
According to an L.A. Times archived article from that time period Sam Walton was the richest man in 1985 America. At that time Walton was worth an estimated $2.8 billion. Alternate Biff Tannen is "one of the richest" men in America. Forbes listed 14 billionaires in America for 1985. Since the "one of the richest" comes from a source heavily biased in favor of Biff Tannen I assume there is some exaggeration. If Biff Tannen had been 1985's 400th richest man in America that would have made his estimated wealth at around $150 million. Frankly I would be surprised if alternate 1985 Tannen had been closer to a billion than half a billion.
Biff Tannen may have been the richest man in alternate 1985 Hill Valley. Possibly the wealthiest man of that timeline's California. Maybe Tannen had more money than anyone else west of the Mississippi River. Biff Tannen on the list of the top 40 richest men in the entire United States might be too much of a stretch. Biff Tannen's hedonistic lifestyle wouldn't have been thrifty. The sports almanac doesn't give future stock market data. There were six recessions between 1958 and 1985. There would have been several economic pitfalls Biff Tannen would have had to navigate through.
I guess as long as alternate 1985 Biff has his casino he'll be just fine. Nobody ever goes broke owning a casino.
