Who’s going to win the medal haul at the 2016 Rio Olympics? Today there are predictive models for everything: what film will win Best Picture at the Oscars, who will win a presidential campaign, and of course, what team will win a given sporting championship. The Olympics are also fair game.

Already, various experts and organizations have made their predictions on which nations will take home the lion’s share of the gold, silver and bronze medals at the 2016 Summer Games. As the website Topend Sports notes, the results of four well-known Olympic prognosticators have similar conclusions: The USA and China will vie for domination, while Russia, Great Britain and Germany make hay as well. In Asia, Japan is expected to do well as a prelude to the 2020 Games in Tokyo. Unfortunately, but perhaps not surprising, host Brazil is not expected to finish in the top ten.

But predictions are predictions – most of these based on past performance data. As the site LiveScience wrote, “there are still variables left unaccounted for.” Until recently, the Russian track and field team were considered viable participants. But on June 17, 2016, the IAAF threw the monkey wrench into the Russian dream machine by declaring the entire Russian track and field team banned from the 2016 Rio Olympics due to state-sponsored doping of Russian athletes.

At the London Olympics four years ago, Russian track and field athletes took home a total of 18 medals, of which 8 were gold. That will drop Russia’s medals chances drastically, and boost the totals of its rivals.

As Nobel Prize winning nuclear physicist, Niels Bohr, famously said, “prediction is very difficult, especially if it’s about the future.”