October 3, 2019

Rugby World Cup Predictions 4

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Team Ratings 4

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 season.

Current Rating Rating at Season Start Difference
New Zealand 27.80 27.60 0.20
England 19.27 19.78 -0.50
South Africa 17.93 18.51 -0.60
Wales 12.66 12.72 -0.10
Ireland 11.59 12.12 -0.50
Australia 9.02 8.70 0.30
France 7.05 7.11 -0.10
Scotland 5.54 5.44 0.10
Argentina 3.52 4.15 -0.60
Japan -6.99 -7.67 0.70
Italy -7.70 -8.57 0.90
Fiji -8.61 -5.27 -3.30
Samoa -13.40 -11.89 -1.50
Georgia -16.37 -17.43 1.10
USA -16.64 -16.38 -0.30
Tonga -19.00 -20.46 1.50
Uruguay -33.65 -35.67 2.00
Canada -34.17 -32.45 -1.70
Russia -35.51 -36.78 1.30
Namibia -40.57 -41.80 1.20

 

Performance So Far

So far there have been 20 matches played, 18 of which were correctly predicted, a success rate of 90%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Japan vs. Russia Sep 20 30 – 10 35.60 TRUE
2 Australia vs. Fiji Sep 21 39 – 21 14.00 TRUE
3 France vs. Argentina Sep 21 23 – 21 3.00 TRUE
4 New Zealand vs. South Africa Sep 21 23 – 13 9.10 TRUE
5 Italy vs. Namibia Sep 22 47 – 22 33.20 TRUE
6 Ireland vs. Scotland Sep 22 27 – 3 6.70 TRUE
7 England vs. Tonga Sep 22 35 – 3 40.20 TRUE
8 Wales vs. Georgia Sep 23 43 – 14 30.10 TRUE
9 Russia vs. Samoa Sep 24 9 – 34 -23.50 TRUE
10 Fiji vs. Uruguay Sep 25 27 – 30 30.00 FALSE
11 Italy vs. Canada Sep 26 48 – 7 23.10 TRUE
12 England vs. USA Sep 26 45 – 7 35.40 TRUE
13 Argentina vs. Tonga Sep 28 28 – 12 24.00 TRUE
14 Japan vs. Ireland Sep 28 19 – 12 -16.30 FALSE
15 South Africa vs. Namibia Sep 28 57 – 3 59.50 TRUE
16 Georgia vs. Uruguay Sep 29 33 – 7 15.40 TRUE
17 Australia vs. Wales Sep 29 25 – 29 -3.60 TRUE
18 Scotland vs. Samoa Sep 30 34 – 0 15.60 TRUE
19 France vs. USA Oct 02 33 – 9 23.60 TRUE
20 New Zealand vs. Canada Oct 02 63 – 0 61.70 TRUE

 

Predictions 4

Here are the predictions. The prediction is my estimated expected points difference with a positive margin being a win to the home team, and a negative margin a win to the away team.

Game Date Winner Prediction
1 Georgia vs. Fiji Oct 03 Fiji -7.80
2 Ireland vs. Russia Oct 03 Ireland 47.10
3 South Africa vs. Italy Oct 04 South Africa 25.60
4 Australia vs. Uruguay Oct 05 Australia 42.70
5 England vs. Argentina Oct 05 England 15.80
6 Japan vs. Samoa Oct 05 Japan 12.90
7 New Zealand vs. Namibia Oct 06 New Zealand 68.40
8 France vs. Tonga Oct 06 France 26.10
9 South Africa vs. Canada Oct 08 South Africa 52.10
10 Argentina vs. USA Oct 09 Argentina 20.20
11 Scotland vs. Russia Oct 09 Scotland 41.10
12 Wales vs. Fiji Oct 09 Wales 21.30
13 Australia vs. Georgia Oct 11 Australia 25.40
14 New Zealand vs. Italy Oct 12 New Zealand 35.50
15 England vs. France Oct 12 England 12.20
16 Ireland vs. Samoa Oct 12 Ireland 25.00
17 Namibia vs. Canada Oct 13 Canada -6.40
18 USA vs. Tonga Oct 13 USA 2.40
19 Wales vs. Uruguay Oct 13 Wales 46.30
20 Japan vs. Scotland Oct 13 Scotland -6.00

 

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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
    Hamish Ji

    I don’t understand how you mark your tips as TRUE if you’re way off the points prediction.

    5 years ago

  • avatar
    Rugby Sceptic

    I have had a look at your previous answer, that your “TRUE” is on the basis that you picked a winner.

    In fairness, your statistical modelling isn’t exactly compelling because you are fundamentally picking heavy favourites.

    Ultimately, your statistical model is really just taking the lines provided by betting companies.

    5 years ago

    • avatar
      David Scott

      Well it would be a bit strange if my predictions were wildly different from the betting companies.

      Point is, a very simple statistical model based on exponential smoothing can do a very good job at predicting.

      5 years ago

  • avatar
    Liam Jack

    Hi David,

    Thank you for the predictions and posting the weeks ahead of time. This helps great.

    Thanks

    5 years ago

  • avatar
    James cook

    If you use these predictions for pint start bets they work well and you can almost make double your money 👍

    5 years ago

  • avatar
    Christopher Williamson

    Hi David, I would like to know how you calculated the teams estimated ratings?

    Any papers/articles around this?

    5 years ago

  • avatar
    Chantelle Haupt

    Possible to rerun these tests after each round to account for the most recent wins? Especially since Japan is winning many matches due to home ground advantage etc.?

    Love the article!

    5 years ago

    • avatar
      David Scott

      I have been updating irregularly to ensure that I always have the latest ratings for all teams prior to them playing. So for example my 6th set of predictions just posted update the ratings of the USA and Wales prior to their games today by taking into account their games on October 9.

      5 years ago

  • avatar
    Wanna winn

    Is it cheating to use your predictions to make my picks in our office tournament results guessing competition?

    5 years ago

  • avatar
    Juandre Welgemoed

    Predictions for 2019 RWC semi-finals?

    5 years ago