Posts from March 2021 (28)

March 9, 2021

NRL Predictions for Round 1

Team Ratings for Round 1

I have decided to not give home ground advantage to the Warriors for any games played at their Australian base on the Central Coast of New South Wales. I will treat all those games as being played on neutral ground.

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 14.53 14.53 -0.00
Roosters 10.25 10.25 0.00
Panthers 8.88 8.88 0.00
Rabbitohs 7.73 7.73 -0.00
Raiders 6.98 6.98 0.00
Eels 1.68 1.68 -0.00
Sharks -0.76 -0.76 0.00
Warriors -1.84 -1.84 0.00
Knights -2.61 -2.61 -0.00
Wests Tigers -3.07 -3.07 -0.00
Sea Eagles -4.77 -4.77 -0.00
Dragons -4.95 -4.95 0.00
Titans -7.22 -7.22 0.00
Bulldogs -7.62 -7.62 -0.00
Cowboys -8.05 -8.05 -0.00
Broncos -11.16 -11.16 -0.00

 

Predictions for Round 1

Here are the predictions for Round 1. 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 Storm vs. Rabbitohs Mar 11 Storm 9.80
2 Knights vs. Bulldogs Mar 12 Knights 8.00
3 Broncos vs. Eels Mar 12 Eels -9.80
4 Warriors vs. Titans Mar 13 Warriors 5.40
5 Roosters vs. Sea Eagles Mar 13 Roosters 18.00
6 Panthers vs. Cowboys Mar 13 Panthers 19.90
7 Raiders vs. Wests Tigers Mar 14 Raiders 13.00
8 Dragons vs. Sharks Mar 14 Sharks -1.20

 

March 3, 2021

Is four a lot?

Q: Is four a lot?

A: Depends on the context. Lockdowns, yes. Incursions per 46000 people through MIQ, no.

Q: We’ve had four lockdowns in Auckland, right?

A: Yes

Q: And how many cases let through MIQ for each 46000 people?

A: About four

Q:

A:

Q: ಠ_ಠ

A: My point, and I do have one, is that more people need to say what their criteria are. If you think four lockdowns is unacceptable, what’s your target that you can argue a realistic system would achieve? If you think 10 cases in 115000 MIQ visitors is a good result, what would it take to be a bad result?

Q: So what’s your threshold?

A: I don’t know. That’s why I haven’t been making comments about the overall performance being good or bad.

March 2, 2021

Briefly

  • About 140% of Kiwis aged 20-24 are on Facebook (NZ$ Herald) — more precisely, that’s the ratio of Facebook’s claimed “reach” to StatsNZ’s population estimates.  This is an age group where the census does relatively badly, but nowhere near that badly.
  • The false-positive rate of the PCR tests for Covid has become topical again, so it’s worth revisiting how we know it is very low. In addition to knowing it should be low based on how the test works, we have simple, direct evidence that the false positive rate is low for the test as used in NZ. We have so far performed 1,720,909 tests in New Zealand and 1,717,865 of them, or 99.8%, have been negative. The 0.2% left over include all the true positives (including people with serious Covid cases), all the inconclusive results, and any false positives.
  • Business$ Week reports on the countries of origin of Covid cases in MIQ.  As you’d expect, the top four are four of the top five in the world for Covid cases: US, India, UK, Russia. Brazil, the other country in the top five, doesn’t show up, but we don’t get as many immigrants or visitors from South America.  Also, as you’d expect, China is very low on the list, because we didn’t start the MIQ system until after they’d controlled their big outbreak. Image (from tweet by @victoriayoung03)

Trusting the wrong data

According to the Guardian (and various other sources), the Pfizer Covid vaccine “may be” less effective in people with obesity, based on an Italian study of antibody levels in 248 vaccinated healthcare workers, 26 of whom were classified as obese and  56 more as overweight.

In the actual randomised clinical trial of the Pfizer vaccine, there were 13,000* people classified as obese and a further 13,000 classified as overweight.  The trial considered obesity as a factor that might affect the vaccine success.  In people with obesity, the estimated efficacy based on actual Covid cases was 95.4%. In those without, it was 94.8%. This is not mentioned at all in the Guardian story.

It’s quite common for clinical trials to end up with a very non-representative subset of the population where you want to use the treatment.  That’s much less true of the US Covid vaccine trials (apart from being US-biased). They made serious efforts to recruit a wide range of people, and did pretty well.  Any risk factor that’s common in the United States is likely to have been common in the trial population, so it’s already represented in the results — even if the results weren’t specifically reported based on that factor, as they are for obesity.

There’s some good research with careful estimation efforts being made to check that efficacy in practical use matches up to the trial, but just measuring antibodies in a small convenience sample isn’t worth a headline.

 

* There are a bunch of different analysis populations in the trial, so the number will be different in different places. They’re all big.

Top 14 Predictions for Round 18

Team Ratings for Round 18

I apparently missed another rescheduled game. The prediction is given below for completeness.

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
Stade Toulousain 8.56 4.80 3.80
Clermont Auvergne 7.03 3.22 3.80
Racing-Metro 92 6.26 6.21 0.00
La Rochelle 6.25 2.32 3.90
Bordeaux-Begles 4.58 2.83 1.80
Lyon Rugby 3.70 5.61 -1.90
RC Toulonnais 3.25 3.56 -0.30
Montpellier 1.01 2.30 -1.30
Stade Francais Paris -0.71 -3.22 2.50
Castres Olympique -1.58 -0.47 -1.10
Brive -2.78 -3.26 0.50
Section Paloise -4.19 -4.48 0.30
Aviron Bayonnais -6.91 -4.13 -2.80
SU Agen -13.90 -4.72 -9.20

 

Performance So Far

So far there have been 125 matches played, 82 of which were correctly predicted, a success rate of 65.6%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 RC Toulonnais vs. Aviron Bayonnais Feb 27 14 – 16 14.90 FALSE
2 La Rochelle vs. Stade Toulousain Feb 28 11 – 14 4.50 FALSE
3 SU Agen vs. Clermont Auvergne Feb 28 16 – 52 -9.90 TRUE

 

Predictions for Round 18

Here are the predictions for Round 18. 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. Lyon Rugby Mar 07 Lyon Rugby -4.10
2 Bordeaux-Begles vs. Section Paloise Mar 07 Bordeaux-Begles 13.50
3 Castres Olympique vs. La Rochelle Mar 07 La Rochelle -0.80
4 Montpellier vs. Clermont Auvergne Mar 06 Montpellier 0.70
5 RC Toulonnais vs. Racing-Metro 92 Mar 07 RC Toulonnais 1.60
6 Stade Francais Paris vs. SU Agen Mar 07 Stade Francais Paris 18.00
7 Stade Toulousain vs. Brive Mar 07 Stade Toulousain 16.00

 

Super Rugby Predictions for Week 3

Team Ratings for Week 3

My automatic updating of scores failed, sorry. Correct results now I hope.

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
Crusaders 14.76 14.49 0.30
Blues 8.45 7.80 0.70
Hurricanes 6.47 7.13 -0.70
Chiefs 4.38 4.38 0.00
Brumbies 2.86 1.47 1.40
Highlanders 2.43 2.70 -0.30
Reds 1.94 1.59 0.30
Rebels -3.16 -3.51 0.40
Waratahs -6.83 -5.02 -1.80
Western Force -13.33 -13.05 -0.30

Performance So Far

So far there have been 6 matches played, 5 of which were correctly predicted, a success rate of 83.3%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Highlanders vs. Crusaders Feb 26 13 – 26 -6.30 TRUE
2 Reds vs. Rebels Feb 26 23 – 21 11.30 TRUE
3 Hurricanes vs. Blues Feb 27 16 – 31 4.80 FALSE
4 Brumbies vs. Waratahs Feb 27 61 – 10 13.00 TRUE

Predictions for Week 3

Here are the predictions for Week 3. 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 Chiefs vs. Highlanders Mar 05 Chiefs 7.50
2 Waratahs vs. Western Force Mar 05 Waratahs 12.00
3 Crusaders vs. Hurricanes Mar 06 Crusaders 13.80
4 Rebels vs. Brumbies Mar 06 Brumbies -0.50

 

Rugby Premiership Predictions for Round 12

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
Exeter Chiefs 6.01 7.35 -1.30
Bristol 3.75 1.28 2.50
Sale Sharks 3.27 4.96 -1.70
Harlequins 1.51 -1.08 2.60
Wasps 0.48 5.66 -5.20
Northampton Saints -0.75 -2.48 1.70
Bath -1.85 2.14 -4.00
Gloucester -2.86 -1.02 -1.80
Leicester Tigers -4.58 -6.14 1.60
London Irish -5.03 -8.05 3.00
Newcastle Falcons -5.78 -10.00 4.20
Worcester Warriors -7.27 -5.71 -1.60

 

Performance So Far

So far there have been 59 matches played, 33 of which were correctly predicted, a success rate of 55.9%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Bristol vs. Leicester Tigers Feb 28 17 – 3 12.60 TRUE
2 Gloucester vs. Worcester Warriors Feb 28 22 – 14 9.10 TRUE
3 Newcastle Falcons vs. Harlequins Feb 28 25 – 22 -3.60 FALSE
4 Northampton Saints vs. Bath Mar 01 22 – 23 6.50 FALSE
5 Sale Sharks vs. Exeter Chiefs Feb 27 25 – 20 1.20 TRUE
6 Wasps vs. London Irish Feb 28 10 – 16 11.90 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 Bath vs. Exeter Chiefs Mar 07 Exeter Chiefs -3.40
2 Harlequins vs. Northampton Saints Mar 08 Harlequins 6.80
3 Leicester Tigers vs. London Irish Mar 06 Leicester Tigers 4.90
4 Sale Sharks vs. Newcastle Falcons Mar 06 Sale Sharks 13.60
5 Wasps vs. Gloucester Mar 07 Wasps 7.80
6 Worcester Warriors vs. Bristol Mar 07 Bristol -6.50

 

Pro14 Predictions for Round 14

Team Ratings for Round 14

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 16.78 16.52 0.30
Munster 10.45 9.90 0.50
Ulster 9.30 4.58 4.70
Edinburgh 3.98 5.49 -1.50
Glasgow Warriors 3.32 5.66 -2.30
Connacht 2.67 0.70 2.00
Scarlets 0.75 1.98 -1.20
Cheetahs -0.46 -0.46 0.00
Cardiff Blues -0.55 0.08 -0.60
Ospreys -1.56 -2.82 1.30
Treviso -6.53 -3.50 -3.00
Dragons -8.55 -7.85 -0.70
Zebre -14.67 -15.37 0.70
Southern Kings -14.92 -14.92 0.00

 

Performance So Far

So far there have been 77 matches played, 52 of which were correctly predicted, a success rate of 67.5%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Treviso vs. Connacht Feb 27 11 – 20 -1.30 TRUE
2 Cardiff Blues vs. Munster Feb 27 25 – 27 -5.00 TRUE
3 Ulster vs. Ospreys Feb 27 21 – 7 18.10 TRUE
4 Edinburgh vs. Scarlets Feb 28 40 – 21 8.80 TRUE
5 Zebre vs. Dragons Feb 28 26 – 15 -0.60 FALSE
6 Leinster vs. Glasgow Warriors Mar 01 17 – 19 21.60 FALSE

 

Predictions for Round 14

Here are the predictions for Round 14. 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 Munster vs. Connacht Mar 06 Munster 12.80
2 Zebre vs. Glasgow Warriors Mar 07 Glasgow Warriors -11.50
3 Ospreys vs. Dragons Mar 07 Ospreys 12.00
4 Ulster vs. Leinster Mar 07 Leinster -2.50
5 Edinburgh vs. Treviso Mar 08 Edinburgh 17.00