August 4, 2021

NRL Predictions for Round 21

Team Ratings for Round 21

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
Storm 24.13 14.53 9.60
Rabbitohs 11.22 7.73 3.50
Panthers 10.86 8.88 2.00
Sea Eagles 9.02 -4.77 13.80
Roosters 7.02 10.25 -3.20
Eels 6.64 1.68 5.00
Titans -1.88 -7.22 5.30
Raiders -2.20 6.98 -9.20
Sharks -3.68 -0.76 -2.90
Wests Tigers -5.32 -3.07 -2.30
Warriors -5.64 -1.84 -3.80
Knights -5.92 -2.61 -3.30
Dragons -8.34 -4.95 -3.40
Broncos -11.32 -11.16 -0.20
Cowboys -11.86 -8.05 -3.80
Bulldogs -14.73 -7.62 -7.10

 

Performance So Far

So far there have been 152 matches played, 109 of which were correctly predicted, a success rate of 71.7%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Roosters vs. Eels Jul 29 28 – 0 -5.20 FALSE
2 Wests Tigers vs. Warriors Jul 30 16 – 18 0.90 FALSE
3 Broncos vs. Cowboys Jul 30 37 – 18 0.30 TRUE
4 Dragons vs. Rabbitohs Jul 31 14 – 50 -16.10 TRUE
5 Knights vs. Raiders Jul 31 34 – 24 -6.60 FALSE
6 Storm vs. Panthers Jul 31 37 – 10 10.40 TRUE
7 Bulldogs vs. Titans Aug 01 6 – 34 -13.30 TRUE
8 Sharks vs. Sea Eagles Aug 01 22 – 40 -11.50 TRUE

 

Predictions for Round 21

Here are the predictions for Round 21. 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 Knights vs. Broncos Aug 05 Knights 5.40
2 Raiders vs. Dragons Aug 06 Raiders 6.10
3 Eels vs. Rabbitohs Aug 06 Rabbitohs -4.60
4 Warriors vs. Sharks Aug 07 Sharks -2.00
5 Roosters vs. Panthers Aug 07 Panthers -3.80
6 Sea Eagles vs. Storm Aug 07 Storm -15.10
7 Bulldogs vs. Wests Tigers Aug 08 Wests Tigers -9.40
8 Titans vs. Cowboys Aug 08 Titans 13.00

 

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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 »