August 20, 2014

NRL Predictions for Round 24

Team Ratings for Round 24

The basic method is described on my Department home page. I have made some changes to the methodology this year, including shrinking the ratings between seasons.

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
Rabbitohs 12.31 5.82 6.50
Cowboys 8.42 6.01 2.40
Roosters 8.31 12.35 -4.00
Sea Eagles 7.28 9.10 -1.80
Storm 6.12 7.64 -1.50
Warriors 4.45 -0.72 5.20
Panthers 2.51 -2.48 5.00
Broncos 1.76 -4.69 6.40
Dragons -1.60 -7.57 6.00
Knights -2.10 5.23 -7.30
Bulldogs -3.37 2.46 -5.80
Titans -4.27 1.45 -5.70
Eels -6.70 -18.45 11.80
Sharks -10.20 2.32 -12.50
Raiders -10.43 -8.99 -1.40
Wests Tigers -14.28 -11.26 -3.00

 

Performance So Far

So far there have been 168 matches played, 96 of which were correctly predicted, a success rate of 57.1%.

Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Rabbitohs vs. Broncos Aug 14 42 – 16 12.60 TRUE
2 Eels vs. Bulldogs Aug 15 16 – 18 2.00 FALSE
3 Raiders vs. Dragons Aug 16 16 – 34 -1.30 TRUE
4 Storm vs. Sharks Aug 16 48 – 6 16.40 TRUE
5 Wests Tigers vs. Roosters Aug 16 4 – 48 -12.80 TRUE
6 Knights vs. Warriors Aug 17 28 – 22 -4.00 FALSE
7 Titans vs. Sea Eagles Aug 17 12 – 15 -8.10 TRUE
8 Panthers vs. Cowboys Aug 18 23 – 22 -2.10 FALSE

 

Predictions for Round 24

Here are the predictions for Round 24. 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 Bulldogs vs. Wests Tigers Aug 21 Bulldogs 15.40
2 Eels vs. Sea Eagles Aug 22 Sea Eagles -9.50
3 Broncos vs. Knights Aug 23 Broncos 8.40
4 Rabbitohs vs. Cowboys Aug 23 Rabbitohs 8.40
5 Warriors vs. Roosters Aug 24 Warriors 0.60
6 Sharks vs. Raiders Aug 24 Sharks 4.70
7 Dragons vs. Titans Aug 24 Dragons 7.20
8 Panthers vs. Storm Aug 25 Panthers 0.90

 

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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
    Dylan Yy

    You predicted the Sea Eagles to win by 8.10 pts, but they only won by 3. How is that prediction marked TRUE?

    4 months ago Reply

    • avatar

      Because I predicted the Sea Eagles would win and they did. Do you think anyone can pretend to predict the exact margin? The predicted margin is there to give an idea of how likely the predicted result is. I could give a probability of the result being as predicted but I don’t.

      4 months ago Reply

  • avatar
    Jean Dupont (a french guy... sorry if my english is not the best)

    Hello M.Scott. I’ve been reading your predictions for 1 month, and this is great job.

    I can’t find your prediction for this week ITM cup round 3. Can you fix please ? (or link me as the answer if they are here and i was not able to find them) Thank you.

    I feel like you should expect some surprises for NRL round 25 & 26 because people’s way to think are linked to real world and not stats… some teams could throw away the game because they are yet qualified for final phases and will give rest to some key players. And some team could intend to avoid to play their worst opponent and plan to throw away one game or two. So they could give errors and create some kind of noise making you think the mathematic model is not so good.
    Why not removing round 25 & 26 to check wheter you get better rate of succes ?

    4 months ago Reply

    • avatar

      I usually post my predictions on a Wednesday morning, but with the ITM Cup round starting on Wednesday evening each week, I will try and post on a Tuesday in future.

      It is very difficult to accommodate perverse team behaviour into predictions and I don’t even try. The NRL is very hard to predict in any case, so it would be hard to know if unusual results in the last 2 rounds were due to attempted gaming of the system.

      4 months ago Reply

  • avatar
    William Stone

    What is your prediction for the total points in the Roosters Storm game?

    4 months ago Reply

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