October 5, 2011

Rugby World Cup 2011 predictions from David Scott …

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Ratings at the Start of RWC 2011

Here are the team ratings at the start of RWC 2011.

  Rating
New Zealand 30.92
Australia 22.97
South Africa 20.50
England 13.19
France 11.42
Wales 9.99
Ireland 8.65
Argentina 6.42
Scotland 4.50
Italy -2.78
Samoa -7.38
Canada -15.03
Tonga -15.11
Fiji -15.70
Japan -22.52
Georgia -25.35
USA -27.29
Romania -28.18
Russia -33.12
Namibia -38.21

Of interest in this table is that the eight top-ranked teams are the ones which have progressed to the quarter finals.

Current Team Ratings

Here are the team ratings as of October 05, 2011

  Rating
New Zealand 31.55
Australia 21.39
South Africa 21.20
Wales 14.71
England 13.78
Ireland 10.79
France 8.91
Argentina 5.56
Scotland 2.25
Samoa -3.67
Italy -4.34
Tonga -11.34
Canada -16.43
Fiji -20.17
Georgia -21.62
Japan -23.03
USA -26.09
Romania -29.39
Russia -33.31
Namibia -42.87

The most notable change here is the improvement of Wales taking it above England. Ireland has also improved, but France is down. Of the lesser teams, Samoa, Tonga and Georgia have improved, Fiji has declined and Namibia has deservedly sunk further into the mire.

Performance So Far

So far there have been 40 matches played, 36 of which were correctly predicted, a success rate of 90%.
Here are the predictions for the games so far.

  Game Date Score Prediction Correct
1 New Zealand vs. Tonga Sep 09 41 – 10 51.03 TRUE
2 Argentina vs. England Sep 10 9 – 13 -6.77 TRUE
3 Fiji vs. Namibia Sep 10 49 – 25 22.51 TRUE
4 France vs. Japan Sep 10 47 – 21 33.94 TRUE
5 Scotland vs. Romania Sep 10 34 – 24 32.68 TRUE
6 Australia vs. Italy Sep 11 32 – 6 25.75 TRUE
7 Ireland vs. USA Sep 11 22 – 10 35.93 TRUE
8 South Africa vs. Wales Sep 11 17 – 16 10.51 TRUE
9 Samoa vs. Namibia Sep 14 49 – 12 30.95 TRUE
10 Scotland vs. Georgia Sep 14 15 – 6 28.04 TRUE
11 Tonga vs. Canada Sep 14 20 – 25 1.53 FALSE
12 Russia vs. USA Sep 15 6 – 13 -7.75 TRUE
13 New Zealand vs. Japan Sep 16 83 – 7 56.20 TRUE
14 Argentina vs. Romania Sep 17 43 – 8 33.00 TRUE
15 Australia vs. Ireland Sep 17 6 – 15 16.26 FALSE
16 South Africa vs. Fiji Sep 17 49 – 3 35.32 TRUE
17 England vs. Georgia Sep 18 41 – 10 36.79 TRUE
18 France vs. Canada Sep 18 46 – 19 25.29 TRUE
19 Wales vs. Samoa Sep 18 17 – 10 17.64 TRUE
20 Italy vs. Russia Sep 20 53 – 17 30.27 TRUE
21 Tonga vs. Japan Sep 21 31 – 18 9.44 TRUE
22 South Africa vs. Namibia Sep 22 87 – 0 59.41 TRUE
23 Australia vs. USA Sep 23 67 – 5 46.40 TRUE
24 England vs. Romania Sep 24 67 – 3 39.03 TRUE
25 New Zealand vs. France Sep 24 37 – 17 24.98 TRUE
26 Argentina vs. Scotland Sep 25 13 – 12 5.63 TRUE
27 Fiji vs. Samoa Sep 25 7 – 27 -10.39 TRUE
28 Ireland vs. Russia Sep 25 62 – 12 42.28 TRUE
29 Wales vs. Namibia Sep 26 81 – 7 50.92 TRUE
30 Canada vs. Japan Sep 27 23 – 23 9.11 FALSE
31 Italy vs. USA Sep 27 27 – 10 24.34 TRUE
32 Georgia vs. Romania Sep 28 25 – 9 5.16 TRUE
33 South Africa vs. Samoa Sep 30 13 – 5 28.08 TRUE
34 Australia vs. Russia Oct 01 68 – 22 56.36 TRUE
35 England vs. Scotland Oct 01 16 – 12 12.96 TRUE
36 France vs. Tonga Oct 01 14 – 19 25.06 FALSE
37 Argentina vs. Georgia Oct 02 25 – 7 28.92 TRUE
38 Ireland vs. Italy Oct 02 36 – 6 12.30 TRUE
39 New Zealand vs. Canada Oct 02 79 – 15 50.88 TRUE
40 Wales vs. Fiji Oct 02 66 – 0 28.95 TRUE

 

Predictions for the Quarter Finals

Here are the predictions for the quarter final games

  Game Date Winner Prediction
1 Ireland vs. Wales Oct 08 Wales -3.90
2 England vs. France Oct 08 England 4.90
3 South Africa vs. Australia Oct 09 Australia -0.20
4 New Zealand vs. Argentina Oct 09 New Zealand 31.00

Most interesting here is the very narrow gap between South Africa and Australia. That game could clearly go either way.

Source File: hwriterPredictions.R

(Page generated on Wed Oct 05 13:39:15 2011 by hwriter 1.3)

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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
    Tony Cooper

    The problem for statisticians is that in the pool stages the games were mostly uneven so that they were mostly predictable. For example my cat could have achieved 87.5% correct just by using the IRB world rankings and predicting that the higher ranked team would beat the lower ranked team.

    A better test would be to predict the spread – then the odds for each game are roughly 50%. That would sort out the cats from the octopuses.

    13 years ago

  • avatar
    Hemant Bandhu

    Hello

    I read your article with great interest, please tell me how have you computed these prediction figures?

    Thanks.

    13 years ago

    • avatar
      David Scott

      The method is exponential smoothing, plus a home ground advantage which for this tournament only applies to New Zealand

      13 years ago