Stats Chat

Team Ratings for Postponed Games

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.

Performance So Far

So far there have been 105 matches played, 67 of which were correctly predicted, a success rate of 63.8%.
Here are the predictions for last week’s games.

Predictions for Postponed Games

Here are the predictions for Postponed Games. 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.

Team Ratings for Round 8

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.

Performance So Far

So far there have been 37 matches played, 21 of which were correctly predicted, a success rate of 56.8%.
Here are the predictions for last week’s games.

Predictions for Round 8

Here are the predictions for Round 8. 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.

Team Ratings for Postponed Matches

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.

Performance So Far

So far there have been 63 matches played, 43 of which were correctly predicted, a success rate of 68.3%.
Here are the predictions for last week’s games.

Predictions for Postponed Matches

Here are the predictions for Postponed Matches. 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.

There was a mysterious piece of vaccine news yesterday when German paper Handelsblatt claimed that the Oxford/AstraZeneca vaccine wasn’t going to be approved in Europe for people over 65 because it had only 8% efficacy in that group.  From the start, he claim of 8% efficacy was clearly either misquoted or misleadingly calculated, but it caused quite a bit of angst — and it is quite possible that the vaccine won’t be approved for older people

The problem is that the vaccine basically wasn’t tested in older people.  In contrast to the Moderna and Pfizer trials, the Oxford/AstraZeneca trials mostly recruited people under 55. The set of four trials reported in December had 428 people over 70, and fewer than 600 between 55 and 70.  Exactly none of these people had the low-dose first injection where the vaccine looked more effective. There’s more data from additional trials, eg in India, but still not very many older people recruited. In fact, about 8%^* of all the trial participants were over 65.

Testing in older people is valuable because they’re the single most important group to vaccinate, and because the immune system changes with age.  It’s always possible that a vaccine will be less effective in older people, because they won’t generate as good an antibody response. In normal circumstances, a vaccine with trial data like this would probably be approved with some upper age limit — partly because of real uncertainty and partly because you want to discourage manufacturers from doing trials that don’t include the most important target populations.

Right now, though, we’re seriously short of vaccines. The trials confirm the Oxford/AstraZeneca vaccine does produce good concentrations of antibodies in older people, so there’s reason to expect it will prevent disease. As an additional encouragement, the two mRNA vaccines didn’t show any signs of being importantly less effective with age.  Soon there should be data from a Johnson & Johnson vaccine using the same basic technology as the Oxford vaccine, and it will be even more reassuring if that is effective in older people.  All in all, it wouldn’t be unreasonable to use the Oxford vaccine at least in the short term, but it’s not really surprising that there’s a controversy.

It is more surprising that Handelsblatt would get the facts so badly wrong.

Update:  An actual table with actual data has escaped on to the internet, saying that the point estimate for efficacy in 65+ year olds is 6.3%, with a confidence interval from -1400% to 94%. That is, the vaccine could make you 14 times more likely or 19 times less likely to get Covid, or anything in between. That still doesn’t really explain where the 8% number came from, but it does show the basic problem that there just isn’t direct information on efficacy in older people.  You have to either rely on the antibody levels, or not. 

^* No, that apparently isn’t just a coincidence

Team Ratings for Round 15

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.

Performance So Far

So far there have been 100 matches played, 65 of which were correctly predicted, a success rate of 65%.
Here are the predictions for last week’s games.

Predictions for Round 15

Here are the predictions for Round 15. 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.

Team Ratings for Postponed Matches

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.

Performance So Far

So far there have been 62 matches played, 41 of which were correctly predicted, a success rate of 66.1%.
Here are the predictions for last week’s games.

Predictions for Postponed Matches

Here are the predictions for Postponed Matches. 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.

Team Ratings for the Currie Cup Final

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.

Note that Cheetahs2 refers to the Cheetahs team when there is a Pro14 match. The assumption is that the team playing in the Pro14 is the top team and the Currie Cup team is essentially a second team. Possibly there will be no such clashes this year

Performance So Far

So far there have been 21 matches played, 16 of which were correctly predicted, a success rate of 76.2%.
Here are the predictions for last week’s games.

Predictions for the Currie Cup Final

Here are the predictions for the Currie Cup Final. 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.

DOT loves data has produced an analysis of alcohol consumption in NZ last year, and Justin Lester tweeted a graphic.

It’s interesting to see the impact of the lockdowns, though it’s very limiting that that the graphic refers only to liquor stores (and maybe supermarkets?) and is in terms of cash spent rather than alcohol purchased, and is only for the start of the first lockdown. The ‘increase’ includes stocking up for consumption during lockdown, as well as any real increase in consumption.  Obviously, even if total alcohol consumption had remained the same, expenditures at liquor stores would have increased with pubs and restaurants closed. And even if total consumption had decreased it’s possible that expenditures at liquor stores could have increased.

Judging from last year, we should get StatsNZ’s alcohol sales data for 2020 around the end of February, which will allow a more useful comparison.

One positive point about the graphic, though: the areas of the bottle things on the graphic are actually proportional to the numbers they represent. For example, Tauranga City’s number  went up 115%, and the bottle (on my screen) is 715×274 pixels compared to 490×186 pixels for 2019, a factor of 2.15. You often don’t see that.

Team Ratings for Round 19

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.

Performance So Far

So far there have been 93 matches played, 61 of which were correctly predicted, a success rate of 65.6%.
Here are the predictions for last week’s games.

Predictions for Round 19

Here are the predictions for Round 19. 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.

Team Ratings for Postponed Matches

Another update because of a rescheduled match. And what is even weirder, another match listed as a Round 12 match. Can the season get any more messed up?

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.

Performance So Far

So far there have been 57 matches played, 38 of which were correctly predicted, a success rate of 66.7%.
Here are the predictions for last week’s games.

Predictions for Postponed Matches

Here are the predictions for Postponed Matches. 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.