The world’s most famous octopus, named Paul, lived in an aquarium in the city of Oberhausen in Germany. Paul achieved worldwide recognition by correctly “predicting” the winner of eight straight matches, including the final, during the 2010 World Cup football tournament in South Africa. Before each match, Paul was presented with two boxes, each containing food. Each container was marked with the flag of one of the two contesting teams. The box which Paul opened first (and ate its contents) was deemed to be the predicted winner of the match.
Unless one believes that octopuses have psychic powers in predicting soccer matches, this is an example of the occurrence of a random event that was deemed very unlikely. The odds for Paul’s impeccable predictions were about 0.39%. Donald Trump’s chances of winning the 2020 elections, based upon probabilities calculated on the basis of a slew of polls published in the past few days, currently stand at about 10%, which is 25 times more than that for Paul’s eight straight predictions in 2010.
So how shocking will it be if Trump pulls of another stunning upset today as he did four years ago? While a Trump victory will be surprising, much more so than four years ago in 2016 when his odds of winning on the morning of election day were 3 times higher than today, statisticians will be quick to point out that events carrying probabilities such as these are, in fact, not that uncommon. Poker players will recognise that Trump’s chances are about 50 times higher than holding a flush. In fact, one sees many instances of random events that are much more improbable than a Trump victory.
How can Trump pull off a stunner today? There are two states that Trump cannot do without. One is Florida and the other is Pennsylvania. It is practically impossible for him to win if he loses either one of these two states. Barring significantly higher polling errors in a number of states, Trump has very few paths to victory. His most likely path will include Florida, Pennsylvania, North Carolina, Georgia, Ohio, Texas and Arizona. He will need to win all of them. If he loses Wisconsin and Michigan, he will need to retain every other state that he won in 2016.
How crucial are these states for Biden? Even if Biden loses Florida, he has almost 4 times as many paths to victory than has Trump. His most likely path will be through Michigan, Wisconsin and Pennsylvania—he will need to rebuild the “Blue Wall” so painfully (for Democrats) torn down by Trump in 2016. Emerging trends from the recent polls seem to indicate that Pennsylvania will be the most crucial state for Biden to win. Biden’s odds of winning the election increase by more than double if he wins Pennsylvania against if he loses.
The election may not be decided for a few days due to the way different states will be counting their mail in ballots, an unprecedented number of which have already been cast. However, Pennsylvania and Florida will be the two states to closely watch today. If Biden establishes a robust lead in either of these states on election night (early morning in India), then the game is over. If these states are close, then the results may not be clear for days as the outcome will be determined by the mail-in ballots and that, in turn, could lead to contested results leading to weeks of legal wranglings. One thing we will know on election night is how accurate the polls have been this election season. Their time of reckoning is here.
The author is Professor and Chair of the UCLA Department of Biostatistics.