May 9, 2023

Top 14 Predictions for Round 25

Team Ratings for Round 25

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
La Rochelle 7.74 6.88 0.90
Stade Toulousain 7.08 6.34 0.70
Bordeaux Begles 4.65 5.27 -0.60
Toulon 4.36 4.09 0.30
Racing 92 3.68 4.86 -1.20
Stade Francais 3.38 -1.05 4.40
Montpellier 2.91 4.18 -1.30
Lyon 2.78 3.10 -0.30
Clermont 1.82 4.05 -2.20
Castres Olympique -0.14 2.87 -3.00
Section Paloise -0.39 -2.12 1.70
Aviron Bayonnais -0.62 -4.26 3.60
USA Perpignan -4.09 -2.75 -1.30
Brive -5.90 -4.20 -1.70

 

Performance So Far

So far there have been 168 matches played, 121 of which were correctly predicted, a success rate of 72%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Clermont vs. Stade Francais May 07 32 – 16 4.10 TRUE
2 Lyon vs. USA Perpignan May 07 41 – 31 13.70 TRUE
3 Montpellier vs. Brive May 07 26 – 27 16.40 FALSE
4 Racing 92 vs. Aviron Bayonnais May 07 55 – 14 8.90 TRUE
5 Section Paloise vs. Castres Olympique May 07 40 – 3 4.30 TRUE
6 Toulon vs. La Rochelle May 07 8 – 23 4.40 FALSE
7 Stade Toulousain vs. Bordeaux Begles May 08 31 – 17 8.40 TRUE

 

Predictions for Round 25

Here are the predictions for Round 25. 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. Clermont May 13 Aviron Bayonnais 4.10
2 Bordeaux Begles vs. Section Paloise May 13 Bordeaux Begles 11.50
3 Brive vs. Castres Olympique May 13 Brive 0.70
4 Montpellier vs. La Rochelle May 13 Montpellier 1.70
5 Racing 92 vs. Toulon May 13 Racing 92 5.80
6 Stade Francais vs. Lyon May 13 Stade Francais 7.10
7 USA Perpignan vs. Stade Toulousain May 13 Stade Toulousain -4.70

 

Super Rugby Predictions for Week 12

Team Ratings for Week 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
Crusaders 16.57 17.95 -1.40
Chiefs 13.12 8.81 4.30
Blues 12.65 12.34 0.30
Hurricanes 9.54 9.59 -0.10
Brumbies 7.31 6.64 0.70
Highlanders 1.66 5.04 -3.40
Reds 0.25 1.89 -1.60
Waratahs -1.28 -2.50 1.20
Rebels -5.71 -6.19 0.50
Western Force -5.92 -5.54 -0.40
Fijian Drua -8.83 -10.50 1.70
Moana Pasifika -10.73 -8.91 -1.80

 

Performance So Far

So far there have been 60 matches played, 45 of which were correctly predicted, a success rate of 75%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Highlanders vs. Chiefs May 05 28 – 52 -6.60 TRUE
2 Fijian Drua vs. Hurricanes May 06 27 – 24 -14.20 FALSE
3 Crusaders vs. Western Force May 06 48 – 13 27.30 TRUE
4 Blues vs. Moana Pasifika May 06 31 – 30 28.90 TRUE
5 Reds vs. Waratahs May 06 24 – 32 6.20 FALSE
6 Rebels vs. Brumbies May 07 26 – 33 -9.90 TRUE

 

Predictions for Week 12

Here are the predictions for Week 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 Chiefs vs. Reds May 12 Chiefs 18.40
2 Western Force vs. Fijian Drua May 12 Western Force 6.40
3 Hurricanes vs. Moana Pasifika May 13 Hurricanes 23.80
4 Crusaders vs. Blues May 13 Crusaders 7.40
5 Waratahs vs. Rebels May 13 Waratahs 7.90
6 Brumbies vs. Highlanders May 14 Brumbies 11.10

 

Rugby Premiership Predictions for the Semi-finals

Team Ratings for the Semi-finals

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
Sale Sharks 6.28 4.14 2.10
Leicester Tigers 5.97 7.93 -2.00
Northampton Saints 2.85 3.99 -1.10
London Irish 2.40 -1.65 4.00
Harlequins 1.28 3.92 -2.60
Saracens 0.83 -5.00 5.80
Bristol 0.33 -2.43 2.80
Wasps -0.18 0.77 -1.00
Exeter Chiefs -1.42 3.67 -5.10
Gloucester -1.80 5.92 -7.70
Bath -2.20 -9.15 6.90
Newcastle Falcons -11.59 -8.76 -2.80
Worcester Warriors -11.69 -12.27 0.60

 

Performance So Far

So far there have been 117 matches played, 80 of which were correctly predicted, a success rate of 68.4%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Bath vs. Saracens May 07 61 – 29 -1.70 FALSE
2 Bristol vs. Gloucester May 07 36 – 21 5.60 TRUE
3 Leicester Tigers vs. Harlequins May 07 17 – 20 10.70 FALSE
4 London Irish vs. Exeter Chiefs May 07 17 – 14 9.10 TRUE
5 Sale Sharks vs. Newcastle Falcons May 07 54 – 12 20.20 TRUE

 

Predictions for the Semi-finals

Here are the predictions for the Semi-finals. 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 Saracens vs. Northampton Saints May 14 Saracens 2.50
2 Sale Sharks vs. Leicester Tigers May 15 Sale Sharks 4.80

 

Currie Cup Predictions for Round 10

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
Pumas 6.79 2.84 3.90
Cheetahs 6.02 4.67 1.30
Sharks 2.05 -1.30 3.40
Western Province 0.02 -3.24 3.30
Bulls -2.27 3.43 -5.70
Griquas -2.39 1.39 -3.80
Lions -6.20 -7.79 1.60
Griffons -14.02 -10.00 -4.00

 

Performance So Far

So far there have been 36 matches played, 24 of which were correctly predicted, a success rate of 66.7%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Griquas vs. Lions May 06 25 – 21 8.50 TRUE
2 Pumas vs. Griffons May 06 45 – 25 25.70 TRUE
3 Cheetahs vs. Western Province May 07 26 – 21 10.90 TRUE
4 Bulls vs. Sharks May 07 27 – 41 1.80 FALSE

 

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 Griffons vs. Western Province May 13 Western Province -10.00
2 Pumas vs. Sharks May 13 Pumas 8.70
3 Griquas vs. Bulls May 14 Griquas 3.90
4 Cheetahs vs. Lions May 14 Cheetahs 16.20

 

May 5, 2023

Old people live longer?

From Ars Technica

An analysis of 2,007 damaged or defective hard disk drives (HDDs) has led a data recovery firm to conclude that “in general, old drives seem more durable and resilient than new drives.”

If you go out and lo0k at human deaths over a period of years, you will also find that Baby Boomers are much more likely die over age 70 than Gen X, and Gen X are more likely to die after 50 than millennials.  It’s too late for Boomers to die young.

Going on, we see that

backup and cloud storage company Backblaze uses hard drives that surpass the average life span Secure Data Recovery saw among the HDDs clients sent it last year. At the end of 2022, Backblaze’s 230,921 hard drives had an average age of 3.6 years versus the 2-year, 10-month average time before failure among the drives Secure Data Recovery worked on last year.

Again, if you look at an older group of people, the average age at death will be older than if you use a younger group.

This all wouldn’t matter so much, except that they are also trying to draw conclusions about novel disk drive technologies being less reliable.  There are statistical techniques to account for the different follow-up time of different groups of drives, but it’s quite possible those techniques would just tell you “nope, too soon to tell”.

May 2, 2023

NRL Predictions for Round 10

 

Team Ratings for Round 10

I have had to update the predictions for this round since I just became aware the games are all being played at Suncorp.

I have to say that this arrangement is blatantly unfair to the non-Brisbane teams which lose a home game advantage but particularly the Sea Eagles, the Sharks and the Warriors on this occasion. The first two teams get to play their home game at the home stadium of their opponents so are doubly disadvantaged regarding home ground advantage. The Warriors have to play their home game across the Tasman and the home ground advantage they lose is greater for them according to my statistical analysis.

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
Panthers 11.52 12.99 -1.50
Rabbitohs 11.41 9.35 2.10
Storm 6.74 11.21 -4.50
Roosters 4.51 7.64 -3.10
Sharks 4.42 4.50 -0.10
Eels 4.22 6.78 -2.60
Raiders 1.47 1.98 -0.50
Broncos -0.71 -5.92 5.20
Cowboys -1.39 6.23 -7.60
Dragons -1.42 -2.73 1.30
Sea Eagles -4.58 -5.26 0.70
Titans -5.58 -6.32 0.70
Dolphins -6.14 -10.00 3.90
Warriors -6.99 -11.12 4.10
Bulldogs -8.54 -8.29 -0.30
Knights -10.04 -9.53 -0.50
Wests Tigers -10.89 -13.52 2.60

 

Performance So Far

So far there have been 72 matches played, 41 of which were correctly predicted, a success rate of 56.9%.
Here are the predictions for last week’s games.

 

Game Date Score Prediction Correct
1 Sharks vs. Cowboys Apr 27 44 – 6 5.20 TRUE
2 Eels vs. Knights Apr 28 43 – 12 15.30 TRUE
3 Broncos vs. Rabbitohs Apr 28 6 – 32 -6.80 TRUE
4 Raiders vs. Dolphins Apr 29 31 – 30 12.10 TRUE
5 Sea Eagles vs. Titans Apr 29 10 – 26 6.70 FALSE
6 Panthers vs. Wests Tigers Apr 29 8 – 12 29.00 FALSE
7 Warriors vs. Roosters Apr 30 0 – 14 -4.10 TRUE
8 Dragons vs. Bulldogs Apr 30 16 – 18 11.90 FALSE

 

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 Bulldogs vs. Raiders May 05 Raiders -10.00
2 Sea Eagles vs. Broncos May 05 Broncos -6.90
3 Warriors vs. Panthers May 06 Panthers -18.50
4 Sharks vs. Dolphins May 06 Sharks 7.60
5 Storm vs. Rabbitohs May 06 Rabbitohs -4.70
6 Wests Tigers vs. Dragons May 07 Dragons -9.50
7 Roosters vs. Cowboys May 07 Roosters 5.90
8 Titans vs. Eels May 07 Eels -9.80

 

Super Rugby Predictions for Week 11

Team Ratings for Week 11

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 16.21 17.95 -1.70
Blues 13.66 12.34 1.30
Chiefs 12.43 8.81 3.60
Hurricanes 10.23 9.59 0.60
Brumbies 7.51 6.64 0.90
Highlanders 2.35 5.04 -2.70
Reds 0.83 1.89 -1.10
Waratahs -1.87 -2.50 0.60
Western Force -5.56 -5.54 -0.00
Rebels -5.92 -6.19 0.30
Fijian Drua -9.51 -10.50 1.00
Moana Pasifika -11.73 -8.91 -2.80

 

Performance So Far

So far there have been 54 matches played, 41 of which were correctly predicted, a success rate of 75.9%.
Here are the predictions for last week’s games.

Game Date Score Prediction Correct
1 Hurricanes vs. Brumbies Apr 28 32 – 27 8.60 TRUE
2 Waratahs vs. Highlanders Apr 28 21 – 20 1.30 TRUE
3 Fijian Drua vs. Blues Apr 29 14 – 30 -17.90 TRUE
4 Moana Pasifika vs. Rebels Apr 29 33 – 43 0.60 FALSE
5 Chiefs vs. Crusaders Apr 29 34 – 24 -1.30 FALSE
6 Reds vs. Western Force Apr 29 31 – 17 9.40 TRUE

 

Predictions for Week 11

Here are the predictions for Week 11. 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 Highlanders vs. Chiefs May 05 Chiefs -6.60
2 Fijian Drua vs. Hurricanes May 06 Hurricanes -14.20
3 Crusaders vs. Western Force May 06 Crusaders 27.30
4 Blues vs. Moana Pasifika May 06 Blues 28.90
5 Reds vs. Waratahs May 06 Reds 6.20
6 Rebels vs. Brumbies May 07 Brumbies -9.90

 

Currie Cup Predictions for Round 9

Team Ratings for Round 9

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
Pumas 7.22 2.84 4.40
Cheetahs 6.47 4.67 1.80
Sharks 0.96 -1.30 2.30
Western Province -0.42 -3.24 2.80
Bulls -1.19 3.43 -4.60
Griquas -2.04 1.39 -3.40
Lions -6.55 -7.79 1.20
Griffons -14.45 -10.00 -4.40

 

Performance So Far

So far there have been 32 matches played, 21 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 Lions vs. Pumas Apr 29 26 – 10 -13.60 FALSE
2 Cheetahs vs. Griffons Apr 29 33 – 10 25.30 TRUE
3 Sharks vs. Griquas Apr 30 24 – 6 5.20 TRUE
4 Western Province vs. Bulls Apr 30 31 – 7 1.80 TRUE

 

Predictions for Round 9

Here are the predictions for Round 9. 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 Griquas vs. Lions May 06 Griquas 8.50
2 Pumas vs. Griffons May 06 Pumas 25.70
3 Cheetahs vs. Western Province May 07 Cheetahs 10.90
4 Bulls vs. Sharks May 07 Bulls 1.80

 

April 27, 2023

Having your say

There’s a 1News headline Only 1 in 4 Aucklanders back Wayne Brown’s sweeping cuts

I was expecting this to be based on proportions supporting the cuts in public submissions, but I was glad to see that the Council commissioned a proper survey in addition to accepting general comments and 1News reported it correctly.  That’s an excellent combination: open public comment allows people to point out problems or solutions you haven’t considered and a survey allows quantitative measurement for issues where you know the options in advance. More organisations should do this.

As you’d expect, trying to get quantitative results from the public comment doesn’t work very well. For example, 1News reported that 40% of submitters didn’t want any cuts, as opposed to the estimate of 7% for all Auckland in the survey.  People who have something to say are more likely to say it.

The number of submissions was very large: more than 10% of the number of votes in the mayoral election.  Even so, the submissions are very unrepresentative. That’s not a problem if you aren’t trying to get quantitative results; having the input biased towards experts and people who care a lot can be helpful.  It would be a problem if you were just counting the results.

April 26, 2023

Missing injuries

Stuff has an important report on road injuries in Auckland, based on a review by Auckland Transport (that doesn’t seem to be available).   They looked at the numbers of serious injuries over three years, both as reported by the police crash analysis system and as reported by the hospitals where the people turned up for treatment. These numbers were not the same

Even the discrepancy for cars is a bit surprising: ‘serious injuries’ here mean hospital admission (an overnight stay).  It’s not clear whether the police are missing half the serious-injury crashes or under-reporting how many people end up in hospital, but I would have expected more completeness of reporting for hospitalisation of people in vehicles. (According to the law, even accidents involving bikes or e-scooters without cars  that result in injury have to be reported to the police, but I’m less surprised this doesn’t happen.)

Some of the bike and pedestrian and ‘transport device’ injuries that are being missed will be crashes that didn’t involve cars.  That’s the dashed/solid distinction in the graph. The data match international research on e-scooter crashes suggesting that most injuries are to the rider, and so may be relatively less likely to get reported to police.  For bikes, a potentially worrying category is injuries involving stationary cars — ‘doorings’ — which might be less likely to get reported than those involving moving cars.

Another important concern, though, is the definition of ‘serious injury’. An injury causing broken bones and resulting in weeks or months of significant disability, but not involving an overnight hospital stay, would not be meet the threshold.  This implies even the MoH statistics are also missing a lot of injuries that a normal person would call ‘serious’.