Posts filed under General (3156)

Team Ratings for Round 20

The basic method is described on my Department home page. I have made some changes to the methodology this year, including shrinking the ratings between seasons.

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 136 matches played, 78 of which were correctly predicted, a success rate of 57.4%.

Here are the predictions for last week’s games.

Predictions for Round 20

Here are the predictions for Round 20. 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 Semi-finals

The basic method is described on my Department home page. I have made some changes to the methodology this year, including shrinking the ratings between seasons.

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 122 matches played, 80 of which were correctly predicted, a success rate of 65.6%.

Here are the predictions for last week’s games.

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.

Thomas Lumley writes in his latest Listener column: “Since 1980, your chance of surviving five years after a heart attack has increased from just over 70% to just under 80%. For breast cancer, the five-year survival rate has gone from about 60% to about 85% in the same period of time, and for melanoma it has risen from about 80% to over 90%.

“From these figures you might conclude that breast cancer treatment has improved a lot, treatment for melanoma has not improved as much and treatment for a heart attack has improved slightly less than for melanoma. It’s actually a bit more complicated than that.”

Read the rest of the column here. 

Team Ratings for Round 19

The basic method is described on my Department home page. I have made some changes to the methodology this year, including shrinking the ratings between seasons.

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 128 matches played, 72 of which were correctly predicted, a success rate of 56.2%.

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 the Qualifying Finals

The basic method is described on my Department home page. I have made some changes to the methodology this year, including shrinking the ratings between seasons.

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 120 matches played, 78 of which were correctly predicted, a success rate of 65%.

Here are the predictions for last week’s games.

Predictions for the Qualifying Finals

Here are the predictions for the Qualifying 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.

I don’t want to get into the general business of election fact-checking, but we have a Stat-of-the-Week  nomination for a statement that is (a) about a specifically statistical issue at the high-school level, and (b) unambiguously wrong.  From Richard Prebble’s “The Letter”:

 Cunliffe is basing Labour’s election campaign around the claim that inequality is growing. Fact check: inequality is falling and New Zealand remains a very equal country. The claim that around a quarter of a million children are in poverty is dubious, to say the very least. Cunliffe says households in poverty have less than 60 percent of the medium income after housing costs. If Bill Gates came to live in New Zealand, the medium income of the country would rise and, according to that logic, more children would be in poverty.

David Cunliffe, as you presumably know, talked about the median, not “medium”; the use of a fraction of median income as a relative poverty threshold is very common internationally. The reason for using the median is precisely that the median income of the country would not rise if a few billionaires were added to the population. The median, the income of the household in the middle of the income distribution, is very insensitive to changes in or additions of a few values. That’s what it’s for.

While I’m writing, I might as well mention the inequality statistics.  Mr Cunliffe isn’t making up his figures on children in poverty; they can be found in the 2014 Household Incomes Report from the Ministry of Social Development [update: that figure is 260000, which matches what The Letter reported was said, but the actual speech said 285000]. The report also gives trends in the Gini index of inequality and in the proportion of income spent on housing.  StatsNZ gives trends in the ratio of 80th to 20th percentile of income, before and after housing costs. The details of trends in inequality depend on how you measure it, but by these measures it is neither falling, nor notably low internationally.

Team Ratings for Round 18

The basic method is described on my Department home page. I have made some changes to the methodology this year, including shrinking the ratings between seasons.

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 122 matches played, 68 of which were correctly predicted, a success rate of 55.7%.

Here are the predictions for last week’s games.

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.

Team Ratings for Round 19

The basic method is described on my Department home page. I have made some changes to the methodology this year, including shrinking the ratings between seasons.

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 113 matches played, 73 of which were correctly predicted, a success rate of 64.6%.

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.

• “There are advantages and disadvantages for reporting the median, but over time it has become common practice worldwide to report market benchmark prices as the median.” from a good explanation at interest.co.nz

• The maximum, on the other hand, is rarely a good summary on its own. This Herald story on slow licence suspensions is not an exception. A median or 90th percentile, or proportion taking longer than a reasonable duration would have been good additions. Also, how many licence suspensions are there for accumulated demerits?

• TheWireless is having a ‘theme’ on Risk. It’s pretty much non-quantitative, which I think misses something, but they aren’t trying to draw unwarranted generalisations from qualitative data. I liked the story on yellow-stickered earthquake-risk buildings; an interesting counterpoint is Eric Crampton’s post on house-hunting in Wellington.

• “Measure twice; cut once” is the old saying. It’s good that the government’s welfare reform program is being evaluated. Not so good that the evaluation plan is secret even under OIA.

• Interestingly, the retracted and recently republished paper on GMOs and Roundup  (previous StatsChat coverage)wasn’t peer-reviewed. Or, rather, it wasn’t peer-reviewed again — the journal decided that the initial review before the retraction was enough. This was not made very clear in the paper or press material.

Team Ratings for Round 17

The basic method is described on my Department home page. I have made some changes to the methodology this year, including shrinking the ratings between seasons.

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 117 matches played, 67 of which were correctly predicted, a success rate of 57.3%.

Here are the predictions for last week’s games.

Predictions for Round 17

Here are the predictions for Round 17. 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.