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December 29, 2020

Top 14 Predictions for Round 13

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Team Ratings for Round 13

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
Racing-Metro 92 7.20 6.21 1.00
Stade Toulousain 6.13 4.80 1.30
La Rochelle 5.08 2.32 2.80
Lyon Rugby 4.79 5.61 -0.80
Clermont Auvergne 4.04 3.22 0.80
RC Toulonnais 3.89 3.56 0.30
Bordeaux-Begles 2.26 2.83 -0.60
Montpellier 1.91 2.30 -0.40
Stade Francais Paris -0.14 -3.22 3.10
Castres Olympique -2.46 -0.47 -2.00
Brive -3.21 -3.26 0.10
Section Paloise -3.40 -4.48 1.10
Aviron Bayonnais -4.85 -4.13 -0.70
SU Agen -10.68 -4.72 -6.00

 

Performance So Far

So far there have been 77 matches played, 53 of which were correctly predicted, a success rate of 68.8%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Brive vs. Lyon Rugby Dec 27 12 – 8 -3.50 FALSE
2 La Rochelle vs. Montpellier Dec 27 22 – 9 8.00 TRUE
3 Racing-Metro 92 vs. SU Agen Dec 27 45 – 10 22.40 TRUE
4 RC Toulonnais vs. Clermont Auvergne Dec 27 27 – 9 4.40 TRUE
5 Section Paloise vs. Stade Francais Paris Dec 27 29 – 27 2.30 TRUE
6 Stade Toulousain vs. Bordeaux-Begles Dec 27 45 – 23 8.40 TRUE

 

Predictions for Round 13

Here are the predictions for Round 13. 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 Aviron Bayonnais vs. Section Paloise Jan 02 Aviron Bayonnais 4.00
2 Bordeaux-Begles vs. RC Toulonnais Jan 02 Bordeaux-Begles 3.90
3 Clermont Auvergne vs. Racing-Metro 92 Jan 02 Clermont Auvergne 2.30
4 Lyon Rugby vs. Castres Olympique Jan 02 Lyon Rugby 12.70
5 Montpellier vs. Stade Toulousain Jan 02 Montpellier 1.30
6 Stade Francais Paris vs. Brive Jan 02 Stade Francais Paris 8.60
7 SU Agen vs. La Rochelle Jan 02 La Rochelle -10.30

 

Rugby Premiership Predictions for Round 5

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Team Ratings for Round 5

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
Exeter Chiefs 9.95 7.35 2.60
Sale Sharks 3.71 4.96 -1.30
Wasps 3.51 5.66 -2.20
Bristol 2.03 1.28 0.70
Bath 0.50 2.14 -1.60
Harlequins -0.97 -1.08 0.10
Gloucester -1.48 -1.02 -0.50
Northampton Saints -2.37 -2.48 0.10
Leicester Tigers -6.21 -6.14 -0.10
Newcastle Falcons -6.89 -10.00 3.10
London Irish -7.17 -8.05 0.90
Worcester Warriors -7.73 -5.71 -2.00

 

Performance So Far

So far there have been 22 matches played, 13 of which were correctly predicted, a success rate of 59.1%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Harlequins vs. Bristol Dec 27 19 – 27 2.70 FALSE
2 Exeter Chiefs vs. Gloucester Dec 27 28 – 20 17.00 TRUE
3 Northampton Saints vs. Worcester Warriors Dec 27 29 – 10 8.70 TRUE
4 Sale Sharks vs. Wasps Dec 28 23 – 26 5.70 FALSE

 

Predictions for Round 5

Here are the predictions for Round 5. 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 Bristol vs. Newcastle Falcons Jan 02 Bristol 13.40
2 Worcester Warriors vs. Harlequins Jan 02 Harlequins -2.30
3 Wasps vs. Exeter Chiefs Jan 03 Exeter Chiefs -1.90
4 Gloucester vs. Sale Sharks Jan 03 Sale Sharks -0.70
5 London Irish vs. Northampton Saints Jan 04 Northampton Saints -0.30
6 Leicester Tigers vs. Bath Jan 04 Bath -2.20

 

Pro14 Predictions for Round 10

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Team Ratings for Round 10

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
Leinster 19.39 16.52 2.90
Munster 10.26 9.90 0.40
Ulster 8.37 4.58 3.80
Edinburgh 3.72 5.49 -1.80
Glasgow Warriors 3.12 5.66 -2.50
Scarlets 2.05 1.98 0.10
Connacht 0.55 0.70 -0.20
Cheetahs -0.46 -0.46 0.00
Cardiff Blues -0.49 0.08 -0.60
Ospreys -3.42 -2.82 -0.60
Treviso -4.26 -3.50 -0.80
Dragons -7.20 -7.85 0.70
Southern Kings -14.92 -14.92 0.00
Zebre -16.71 -15.37 -1.30

 

Performance So Far

So far there have been 46 matches played, 32 of which were correctly predicted, a success rate of 69.6%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Connacht vs. Ulster Dec 27 19 – 32 -1.80 TRUE
2 Dragons vs. Cardiff Blues Dec 27 12 – 13 -1.90 TRUE
3 Ospreys vs. Scarlets Dec 27 14 – 16 -0.10 TRUE

 

Predictions for Round 10

Here are the predictions for Round 10. 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 Treviso vs. Zebre Jan 03 Treviso 17.50
2 Cardiff Blues vs. Ospreys Jan 03 Cardiff Blues 7.90
3 Edinburgh vs. Glasgow Warriors Jan 03 Edinburgh 5.60
4 Leinster vs. Connacht Jan 03 Leinster 23.80
5 Scarlets vs. Dragons Jan 03 Scarlets 14.30
6 Ulster vs. Munster Jan 03 Ulster 3.10

 

Currie Cup Predictions for Round 6

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Team Ratings for Round 6

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
Bulls 7.63 6.16 1.50
Western Province 4.27 5.26 -1.00
Sharks 3.69 5.63 -1.90
Lions 3.46 1.46 2.00
Cheetahs -2.31 -2.96 0.60
Pumas -8.16 -6.66 -1.50
Griquas -8.58 -8.90 0.30

 

Performance So Far

So far there have been 13 matches played, 10 of which were correctly predicted, a success rate of 76.9%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Western Province vs. Griquas Dec 26 34 – 17 17.40 TRUE
2 Cheetahs vs. Sharks Dec 27 37 – 10 -5.60 FALSE

 

Predictions for Round 6

Here are the predictions for Round 6. 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 Pumas vs. Lions Jan 02 Lions -7.10
2 Sharks vs. Griquas Jan 02 Sharks 16.80
3 Cheetahs vs. Western Province Jan 02 Western Province -2.10

 

December 25, 2020

Top 14 Predictions for Round 12

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Team Ratings for Round 12

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
Racing-Metro 92 6.73 6.21 0.50
Stade Toulousain 5.63 4.80 0.80
Lyon Rugby 5.32 5.61 -0.30
La Rochelle 4.73 2.32 2.40
Clermont Auvergne 4.54 3.22 1.30
RC Toulonnais 3.39 3.56 -0.20
Bordeaux-Begles 2.75 2.83 -0.10
Montpellier 2.27 2.30 -0.00
Stade Francais Paris -0.16 -3.22 3.10
Castres Olympique -2.46 -0.47 -2.00
Section Paloise -3.38 -4.48 1.10
Brive -3.73 -3.26 -0.50
Aviron Bayonnais -4.85 -4.13 -0.70
SU Agen -10.21 -4.72 -5.50

 

Performance So Far

So far there have been 71 matches played, 48 of which were correctly predicted, a success rate of 67.6%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Castres Olympique vs. Brive Dec 23 24 – 25 7.30 FALSE

 

Predictions for Round 12

Here are the predictions for Round 12. 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 Brive vs. Lyon Rugby Dec 27 Lyon Rugby -3.50
2 Castres Olympique vs. Aviron Bayonnais Dec 27 Castres Olympique 7.90
3 La Rochelle vs. Montpellier Dec 27 La Rochelle 8.00
4 Racing-Metro 92 vs. SU Agen Dec 27 Racing-Metro 92 22.40
5 RC Toulonnais vs. Clermont Auvergne Dec 27 RC Toulonnais 4.40
6 Section Paloise vs. Stade Francais Paris Dec 27 Section Paloise 2.30
7 Stade Toulousain vs. Bordeaux-Begles Dec 27 Stade Toulousain 8.40

 

December 22, 2020

Currie Cup Predictions for Round 5

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Team Ratings for Round 5

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
Bulls 7.63 6.16 1.50
Sharks 5.76 5.63 0.10
Western Province 4.31 5.26 -1.00
Lions 3.46 1.46 2.00
Cheetahs -4.38 -2.96 -1.40
Pumas -8.16 -6.66 -1.50
Griquas -8.62 -8.90 0.30

 

Performance So Far

So far there have been 11 matches played, 9 of which were correctly predicted, a success rate of 81.8%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Pumas vs. Cheetahs Dec 18 31 – 35 1.80 FALSE
2 Lions vs. Sharks Dec 19 27 – 12 0.20 TRUE

 

Predictions for Round 5

Here are the predictions for Round 5. 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 Western Province vs. Griquas Dec 26 Western Province 17.40
2 Bulls vs. Lions Dec 26 Bulls 8.70
3 Cheetahs vs. Sharks Dec 27 Sharks -5.60

 

December 20, 2020

Good enough that you don’t need statistics?

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From the usually-reliable XKCD

The graphs of cumulative Covid incidence for the Pfizer and Moderna vaccine trials are very impressive: the vaccines are effective.  We need to relabel the axes to see what’s wrong with the cartoon

If the trials had just been about vaccine effectiveness, they would have been much shorter.  Delaying the actual use of the vaccine, when the US alone is getting 1.5 million cases a week, just in order to get a pretty graph and avoid using statistics would be … ethically questionable. No matter how you felt about your high school stats class. If we only cared about effectiveness, the graph would look more like

The reason the trials ran so long was to assess safety.  Everyone in the trials was followed up for six weeks after their second vaccine dose, because that’s long enough to see any adverse reactions that have been seen for past vaccines.  The very high rate of new cases in the US and other countries involved in the trials, together with the high effectiveness, meant that effectiveness could be demonstrated much more quickly than safety — but safety is important.

Safety is especially important for us in NZ, where there is less urgency than in the US or UK.  Medsafe will be looking at whether to approve the vaccines and under what conditions, and they’ll be doing more than “We reject the null hypothesis based on the ‘hot damn, check out this chart’ test.”

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December 17, 2020

Currie Cup Predictions for Round 4

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Team Ratings for Round 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
Bulls 7.63 6.16 1.50
Sharks 6.78 5.63 1.10
Western Province 4.31 5.26 -1.00
Lions 2.44 1.46 1.00
Cheetahs -4.90 -2.96 -1.90
Pumas -7.64 -6.66 -1.00
Griquas -8.62 -8.90 0.30

 

Performance So Far

So far there have been 9 matches played, 8 of which were correctly predicted, a success rate of 88.9%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Western Province vs. Pumas Dec 11 28 – 14 17.00 TRUE
2 Cheetahs vs. Lions Dec 12 23 – 39 -0.70 TRUE
3 Sharks vs. Bulls Dec 12 32 – 29 3.80 TRUE

 

Predictions for Round 4

Here are the predictions for Round 4. 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 Pumas vs. Cheetahs Dec 18 Pumas 1.80
2 Griquas vs. Bulls Dec 19 Bulls -11.80
3 Lions vs. Sharks Dec 19 Lions 0.20

 

December 16, 2020

Covid vaccine #2

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We now have fairly detailed data on the second Covid vaccine, the one from Moderna.

Again, I’ll add more as I see them.

Causes and implications

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From the Herald

A coroner has warned of the dangers of driving while impaired by drugs after reviewing nine fatal vehicle crashes and finding cannabis use was implicated in six of them.

but further down in the story

He was found to be almost five times the legal drink-drive limit while also testing positive for cannabis and its constituent element tetrahydrocannabinol (THC).

At a blood alcohol concentration of 0.25%, your risk of a crash has increased by more than a factor of 100.  That is, more than 99 out of 100 crashes in people with blood alcohol of 0.25% will be caused by the alcohol. You don’t need cannabis use to explain a crash like this, and it’s not clear that there was any relevant cannabis use.  The report says the driver was at a BBQ where people were drinking. There is no suggestion in the story that anyone was smoking weed (though it isn’t specifically ruled out).

The description of testing positive for “cannabis and its constituent element tetrahydrocannabinol” is also a bit weird.  I think they just tested for THC; that’s what I’ve seen in previous reports from ESR, who do the testing.  And they can pick up very small amounts of THC; a 2012 publication on tests after fatal crashes reported a range from approximately 0.1 ng/mL to 44 ng/mL (mean 5.6 ng/mL) concentration in blood samples.  Some of these people will have been impaired by THC, but by no means all of them.  ESR are careful about how they report this sort of thing, and don’t write things like “cannabis use was implicated” when they mean “THC was detectable”, but the coroner seems to be less careful.

The coroner didn’t say anything about alcohol use in the other eight fatal vehicle crashes.  You’d hope, if he’s making those sorts of statements about drugs that some of the crashes didn’t involve large amounts of alcohol and had evidence of recent consumption of cannabis or some other reason to think it was really implicated, but you’d also hope he’d make that clear if it was true.

 

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