I'm real glad I stopped betting on the ABs.
A draw against the Boks and a loss to the ball sanders, the send off was a yellow only, would have cost me a stack.
The ABs are on the slide, and it may get worse at the quarter-final stage.

__________________
At the feast of ego everyone leaves hungry

Now $13 with most bookies

Black Ferns 37 Wallaroos 8
All Blacks 36 Wallabies 0

That's much better

Wales are the new rugby world no. 1 ending the 10-year reign of the All Blacks

Current top 10
1. Wales
2. NZ
3. Ireland
4. South Africa
5. England
6. Australia
7. France
8. Scotland
9. Japan
10. Fiji

Those World Rugby ratings give some really useful info for gambling, much more than just who is ranked higher. World Rugby purposely created the rating system to be predictable. The rating difference is used to get the probability that the higher rated team will beat the lower-rated team, after adding three points to the home team rating. After the game, the ratings are adjusted based on the difference between the actual result and the probability going in. I looked at the last five Rugby WCs. The higher rated teams have won 86% of the non-tied matches. That’s amazing accuracy.

For the WC, add three points to Japan’s rating. Suppose the higher-rated team is d points better. According to World Rugby’s examples, the higher rated team has a probability of winning equal to 0.5 + (d/20). You have to limit that from 0.1 to 0.9.

Let’s look at the current ratings. Wales is tops with 89.43 just barely ahead of NZ with 89.40. That 0.03 advantage means that Wales is .5 + (.03/20) or .5015 likely to beat NZ, making NZ .4985 likely to win. I’d say that’s’ a toss-up. Now, if number 1 Wales (89.43) plays number 3 Ireland (88.69) that 0.74 rating difference means that Wales in .5 + (.74/20) or .537 likely to win. The fair decimal odds would be 1/.537 or 1.86, so you could bet on Wales if is you can find a price of more than 1.86.

When we get closer to the WC, I’ll take the last pre-WC Rugby World ratings and give you the probability of the match-ups in the group phase. We’ll see what that looks like.

Cheers,

Ray Stefani

That would be great Ray, thanks

I promised to give you the predictions for the group phase of the Rugby World Cup, as soon as we had the pre-WC ratings from World Rugby. The final ratings are in, so I attached the game-by-game probabilities, using World Rugby’s system, and then the fair decimal odds which are equal to 1/probabilities. According to the World Rugby system, they add three rating points to the home team rating and then find the rating difference of each team’s rating minus the opponent’s rating. The probability that the team will win is:

.5 + (rating difference)/20

There is a problem though. World Rugby has to cap the rating difference at +10 (or -10) to keep the probability between 1 and zero. I decided to make the limit 0.99 and 0.01, because having World Rugby predicting a probability of 1 just makes me crazy, and we don’t want that.

There are Groups A, B, C and D, each with 5 teams playing four games in a round-robin, so each group plays 10 games. Of the 40 games, 24 are maxed out with winning probabilities of 0.99 and 0.01. The other 16 games are much more competitive. I noticed that 7 of 10 Group A games are maxed out, compared to 8 of 10 in Group B, 3 of 10 in Group C and 6 of 10 in Group D. Group C should be the most competitive. There aren’t going to be many games worth betting on, but those will be hugely important, and keep the pubs busy. When we reach the quarter-finals, the rest of the games ought to be close, but World Rugby will not update ratings until after the WC, so we have to use pre-WC ratings. Of course, you could make big money on some big upsets and buy the first round.

Cheers
,
Ray Stefani

Attached Files

Rugby 2019 WC Predictions (lim .99).docx (18.4 KB, 449 views)

Hi Ray

Can you check or confirm the link to the attached document. It won’t let me open the link

Cheers

worked for me

Fatcat had trouble with the link to the predictions. I am going to try to post directly to this text.

Ray Stefani


Rugby WC Predictions Using Rugby World Ratings (Pwin from .01 to .99)
Team Pwin Fair Odds Team Pwin Fair Odds

Group A
Japan 0.99 1.01 Russia 0.01 100.00
Ireland 0.92 1.08 Scotland 0.08 13.07
Russia 0.29 3.49 Samoa 0.71 1.40
Japan 0.01 86.96 Ireland 0.99 1.01
Scotland 0.99 1.01 Samoa 0.01 100.00
Ireland 0.99 1.01 Russia 0.01 100.00
Japan 0.99 1.01 Samoa 0.01 100.00
Scotland 0.99 1.01 Russia 0.01 100.00
Ireland 0.99 1.01 Samoa 0.01 100.00
Japan 0.44 2.30 Scotland 0.57 1.77

Group B
New Zealand 0.60 1.66 South Afr 0.40 2.52
Italy 0.99 1.01 Namibia 0.01 100.00
Italy 0.99 1.01 Canada 0.01 100.00
South Africa 0.99 1.01 Namibia 0.01 100.00
New Zealand 0.99 1.01 Canada 0.01 100.00
South Africa 0.99 1.01 Italy 0.01 100.00
New Zealand 0.99 1.01 Namibia 0.01 100.00
South Africa 0.99 1.01 Canada 0.01 100.00
New Zealand 0.99 1.01 Italy 0.01 100.00
Namibia 0.49 2.02 Canada 0.51 1.98
 
Group C
France 0.67 1.49 Argentina 0.33 3.04
England 0.99 1.01 Tonga 0.01 100.00
England 0.99 1.01 USA 0.01 100.00
Argentina 0.76 1.31 Tonga 0.24 4.21
France 0.88 1.14 USA 0.12 8.13
England 0.99 1.01 Argentina 0.01 100.00
France 0.93 1.07 Tonga 0.07 15.15
Argentina 0.71 1.42 USA 0.29 3.40
England 0.92 1.09 France 0.08 12.58
USA 0.56 1.80 Tonga 0.44 2.26

Group D
Australia 0.83 1.20 Fiji 0.17 5.92
Wales 0.99 1.01 Georgia 0.01 100.00
Fiji 0.99 1.01 Uruguay 0.01 100.00
Georgia 0.91 1.10 Uruguay 0.09 10.58
Australia 0.34 2.97 Wales 0.66 1.51
Georgia 0.29 3.41 Fiji 0.71 1.41
Australia 0.99 1.01 Uruguay 0.01 100.00
Wales 0.99 1.01 Fiji 0.01 100.00
Australia 0.99 1.01 Georgia 0.01 100.00
Wales 0.99 1.01 Uruguay 0.01 100.00