Posts from July 2016 (39)

Team Ratings for Round 20

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 136 matches played, 84 of which were correctly predicted, a success rate of 61.8%.
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.

Three pieces of statistical good news:

First, from the New York Times,  several serious diseases are getting less common, and we don’t really know why. Heart disease rates have been falling for my whole lifetime. More recently, rates of dementia have been going down (though the number of cases is going up, because there are more old people). Hip fractures are down. And now colon cancer is getting less common.  In all these cases there are well-understood contributing factors, but these aren’t enough to explain the decrease (except perhaps for heart disease).

Violence is also down: in the specific politically-relevant case, fewer US police officers have been shot during the Obama presidency than the equivalent periods of Clinton, Bush, or Reagan.

And finally, in US states where medical marijuana has been legalised, there are fewer prescriptions written for other competing drugs. (Washington Post, original research paper). This is most dramatic in prescriptions for painkillers: marijuana is competing successfully against opioid narcotics.

I mentioned in June that Generation Zero were trying to crowdfund an opinion poll on having a rail option in the Auckland’s new harbour crossing.

Obviously they’re doing this because they think they know what the answer will be, but it’s still a welcome step towards evidence-based lobbying.

The results are out, in a poll conducted by UMR. Well, a summary of the results is out, in a story at The Spinoff, and we can hope the rest of the information turns up on Generation Zero’s website at some point. A rail crossing is popular, even when its cost is presented as part of the question:

The advantage of proper opinion polls over petitions or other sort of bogus polls is the representativeness.  If 50,000 people sign a petition, all you know is that the true number of supporters is at least 50,000 (and maybe not even that).  Sometimes there will be one or two silent supporters for each petition vote (as with Red Peak); sometimes many more; sometimes fewer.

Petitions do have the advantage that you feel as if you’re doing something when you sign, but we can cope without that: after all, we still have social media.

• The Guardian on spotting dodgy political statistics

• Pie are square: an experimental study finding square ‘pie’ charts better than round ones

• The difficulties of getting published papers corrected in science: New York Magazine on ‘psychoticism’ and political views

• How to draw a good map of droughts (severity/frequency)

• Are the political betting markets too stable?

• Lovely rant about Aloe vera gel and sunburn: “Listen, you antiscience monster: These people who sell aloe vera are stealing from you. As of 2004, the market for finished aloe products was worth $110 billion. The aloe barons are taking your money and building gigantic aloe palaces and not helping your sunburn at all. They are probably taking long soaks in great big hot tubs for which you helped pay. And they’re probably wearing lots of sunscreen, too, because they know nothing in their cabinets can heal sunburn.”

• When is AI (data mining/machine learning/etc) appropriate? from mathbabe.org

Each week, we would like to invite readers of Stats Chat to submit nominations for our Stat of the Week competition and be in with the chance to win an iTunes voucher.

Here’s how it works:

• Anyone may add a comment on this post to nominate their Stat of the Week candidate before midday Friday July 22 2016.
• Statistics can be bad, exemplary or fascinating.
• The statistic must be in the NZ media during the period of July 16 – 22 2016 inclusive.
• Quote the statistic, when and where it was published and tell us why it should be our Stat of the Week.

Next Monday at midday we’ll announce the winner of this week’s Stat of the Week competition, and start a new one.

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If you’d like to comment on or debate any of this week’s Stat of the Week nominations, please do so below!

Team Ratings for Round 17

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 126 matches played, 93 of which were correctly predicted, a success rate of 73.8%.
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.

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 130 matches played, 80 of which were correctly predicted, a success rate of 61.5%.
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.

Each week, we would like to invite readers of Stats Chat to submit nominations for our Stat of the Week competition and be in with the chance to win an iTunes voucher.

Here’s how it works:

• Anyone may add a comment on this post to nominate their Stat of the Week candidate before midday Friday July 15 2016.
• Statistics can be bad, exemplary or fascinating.
• The statistic must be in the NZ media during the period of July 9 – 15 2016 inclusive.
• Quote the statistic, when and where it was published and tell us why it should be our Stat of the Week.

Next Monday at midday we’ll announce the winner of this week’s Stat of the Week competition, and start a new one.

(more…)

If you’d like to comment on or debate any of this week’s Stat of the Week nominations, please do so below!