Algorithm predicts Olympic Sevens' win

25 Jul, 2024
 
Algorithm predicts Olympic Sevens' win
Credit: Shutterstock
Niven Winchester, Auckland University of Technology

The speed, skill and flair on display in rugby sevens makes it an ideal Olympic sport. The Paris games should be no exception, especially given France’s own great rugby tradition.

While the conventional 15-a-side game has only ever featured at four Olympics (1900, 1908, 1920 and 1924), sevens debuted at the Rio de Janeiro games in 2016, capturing fans with its festive atmosphere and fast-running athleticism.

And although the traditionally strong rugby-playing nations tend to dominate the sevens version, it also allows the “minnows” to compete and sometimes surprise the heavyweights.

So, which teams are favourites to win medals in Paris? To answer this we’ve used a suite of statistical models known as Rugby Vision. This modelling system has outperformed bookmakers when forecasting outcomes for Rugby World Cup games.

How the prediction model works

Rugby Vision has three components:

  • an algorithm uses past game statistics to rate the strength of each sevens team, based on results from the 2023–24 SVNS international tournaments and other Olympic qualification rounds
  • the ratings (and home advantage for France) are then used to simulate the expected outcome of each game
  • the tournament is simulated 10,000 times to account for uncertainty around expected outcomes.

By examining the number of times in the 10,000 simulations that each team “wins” the tournament, we can calculate the probability of each team winning the gold medal. Both the men’s and women’s tournaments have been analysed this way.

Argentina lead the men’s pack

Medal probabilities for each of the 12 qualified teams in the men’s tournament, which begins on July 24, are displayed below.


Rugby Vision, CC BY-SA

Argentina, which dominated the 2023-24 SVNS, is favourite to win (28.1%) and has a 60.4% chance of earning any medal. France, which has home advantage and won the 2023-24 SVNS grand final, is second favourite (22.3%), followed by Ireland (12.5.%), which was a consistent performer in the 2023–24 SVNS.

Traditional sevens powerhouses Fiji (which won gold at the two previous Olympics) and New Zealand are fourth and fifth favourites respectively. This reflects mixed performances by both teams at the 2023–24 SVNS.

NZ versus Australia for the women’s gold

The women’s tournament kicks off on July 28, with New Zealand (34.8%) and Australia (31.1%) most likely to win gold. Between them, these two teams won seven of the eight 2023–24 SVNS tournaments.

France is third favourite (25.9%), with the USA (4.0%) and Canada (2.2%) rounding out the five most likely winners.


Rugby Vision, CC BY-SA

Although New Zealand has a higher chance than Australia of winning gold, Australia has a higher chance of winning any medal. This is because the algorithm rates Australia a (slightly) stronger team than New Zealand – but New Zealand is expected to have an easier semi-final opponent.

Of course, the algorithm’s favourite does not always win. At the 2023 Rugby World Cup, for example, Rugby Vision ranked New Zealand likeliest to win, with South Africa second. South Africa beat New Zealand in the final.

The same uncertainty applies at the Olympic sevens. While Argentina is favourite to win the men’s tournament, there is still a 72% chance another team will take home the gold. Upsets should be expected – that is why watching sport is so enthralling.


The author acknowledges the assistance of Jensen Fiskin, whose data collection contributed to the forecasts included in this article. The Conversation


Niven Winchester, Professor of Economics, Auckland University of Technology

This article is republished from The Conversation under a Creative Commons license. Read the original article.