October 13, 2015

Rugby World Cup Predictions for the Quarter Finals

Team Ratings for the Quarter Finals

The basic method is described on my Department home page.

Here are the team ratings prior to this week’s games, along with the ratings at the start of the Rugby World Cup.

Current Rating Rating at RWC Start Difference
New Zealand 26.96 29.01 -2.00
South Africa 23.39 22.73 0.70
Australia 21.66 20.36 1.30
Ireland 17.35 17.48 -0.10
England 16.43 18.51 -2.10
Wales 13.30 13.93 -0.60
France 10.41 11.70 -1.30
Argentina 9.89 7.38 2.50
Scotland 5.13 4.84 0.30
Fiji -2.19 -4.23 2.00
Samoa -4.15 -2.28 -1.90
Italy -6.37 -5.86 -0.50
Tonga -8.84 -6.31 -2.50
Japan -9.10 -11.18 2.10
USA -17.13 -15.97 -1.20
Georgia -17.74 -17.48 -0.30
Canada -17.89 -18.06 0.20
Romania -19.44 -21.20 1.80
Uruguay -31.67 -31.04 -0.60
Namibia -33.29 -35.62 2.30

 

Performance So Far

So far there have been 40 matches played, 34 of which were correctly predicted, a success rate of 85%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 New Zealand vs. Tonga Oct 09 47 – 9 35.30 TRUE
2 Samoa vs. Scotland Oct 10 33 – 36 -10.70 TRUE
3 Australia vs. Wales Oct 10 15 – 6 8.20 TRUE
4 England vs. Uruguay Oct 10 60 – 3 54.10 TRUE
5 Argentina vs. Namibia Oct 11 64 – 19 42.80 TRUE
6 Italy vs. Romania Oct 11 32 – 22 13.70 TRUE
7 France vs. Ireland Oct 11 9 – 24 -5.90 TRUE
8 USA vs. Japan Oct 11 18 – 28 -7.60 TRUE

 

Predictions for the Quarter Finals

Here are the predictions for the Quarter Finals. The prediction is my estimated expected points difference with a positive margin being a win to the first-named team, and a negative margin a win to the second-named team.

Game Date Winner Prediction
1 South Africa vs. Wales Oct 17 South Africa 10.10
2 New Zealand vs. France Oct 17 New Zealand 16.60
3 Ireland vs. Argentina Oct 18 Ireland 7.50
4 Australia vs. Scotland Oct 18 Australia 16.50

 

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David Scott obtained a BA and PhD from the Australian National University and then commenced his university teaching career at La Trobe University in 1972. He has taught at La Trobe University, the University of Sheffield, Bond University and Colorado State University, joining the University of Auckland, based at Tamaki Campus, in mid-1995. He has been Head of Department at La Trobe University, Acting Dean and Associate Dean (Academic) at Bond University, and Associate Director of the Centre for Quality Management and Data Analysis at Bond University with responsibility for Short Courses. He was Head of the Department of Statistics in 2000, and is a past President of the New Zealand Statistical Assocation. See all posts by David Scott »

Comments

  • avatar
    Ulises Gasparini

    Just one error: Argentina will win. By 14.

    9 years ago

    • avatar
      Adrien Book

      Hi,

      What makes you say this? Show your work.

      9 years ago

      • avatar
        Ulises Gasparini

        Ireland won’t be able to count with some of their best players, and they didn’t showed so much against the poorest french and Italian sides of the world cup history. The irish defense has not been challenged by aggressive attack yet.
        In the other hand, Argentina’s game has grown a lot during the rwc, since they narrow lost to ABs.
        But the main reason is that I’m a Pumas fan :)

        9 years ago

      • avatar
        Ulises Gasparini

        Take a look at the RWC website. France and Italy has some of the poorest numbers in meters, carries, and tackles (france) for tier 1 countries. Also considering they’re defence oriented teams playing in counter attack position.

        9 years ago

      • avatar
        David Hood

        Going with “Current Highest Rugby Ranking” as a predictor, Ireland would win by around 10 (based on a general regression on results between all countries).

        But, leaning a little harder on the regression residuals, Argentina are scoring better in their matches by about 15 points in pool play than the ranking difference indicates they should while Ireland are as expected or fractionally worse. So a slight nod to Argentina, but the result will be due to a single scoring opportunity.

        Similarly, the expected result of S.A. vs Wales based solely on current ranking is Wales by 2, however South Africa’s ranking is much lower than their scoring suggests it should be (basically, because they played the vastly improved Japanese side so gave some of their rank to Japan) and that scoring above what is expected shifts it strongly into a South African win.

        9 years ago

        • avatar
          Ulises Gasparini

          23 points dofference just because the yellow card. Should be 40.

          9 years ago