IRB World Rankings Confusion

[Dizzy]

Yeah, the All Blacks hammered all their opposition so far and with each game, their IRB world ranking didn't increase one bit. Last week before the game I checked the World Rankings for NZ and SA, they were
New Zealand
91.68
South Africa
89.46

With a difference of 2.22pts

And in the article it said, if the All Blacks were to beat South Africa by 15 pts the All Blacks ranking will increase resulting in a 3.66 pt difference.

Well the All Blacks won by 20pts on the weekend and yet there has been no change on the IRB World Rankings.

Anybody know why?

 

[Draggs]

The current rankings are of July 5th.
The new rankings will probably be up in a few days.

 

[Iron Mike]

They update the rankings every Monday, UK time at 12 o'clock (noon).

 

[Amobokoboko]

Cool, want to see what the difference is between NZ and SA

 

[TRF_Olyy]

Here's how they stand atm:

1(1)

NEW ZEALAND 92.402
(2)

SOUTH AFRICA 88.743
(3)

AUSTRALIA 84.41

 

[Dizzy]

Oh ok, thanks everyone, i didn't realise when they updated em...

 

[Dizzy]

I wonder how much it will increase if the All Blacks defeat them by 15+pts this time..

 

[Dizzy]

nevermind I figured it out they would rise to 93.105

 

[DuncTheDoodle]

So Wales drop 3 places because of two loses at the hands of No. 1, at the time 5 above them. Yet France lose by a bigger margin to SA (Two places above them) and also pretty convincingly to Argentina, who are 4 places bellow them, but don't move. Can somebody explain this? I understand England beating Austrailia and Scotland winning the series brought them up, but this still seems a little odd.

 

[smartcooky]

Dunc

This is because its a "points exchange" system. The winning team gains the same number of points that the losing team loses, and the number of points are calculated according to three criteria plus one extra criteria

1. the relative points of the two sides (NOT their relative positions on the table)
2. home away or neutral venues
3. the winning margin
the extra criteria is that world cup matches count double.

How much positions change often depends on how far apart they are. Its their actual points that determine their position. Here are a couple of extreme examples

Example 1
1. Team A...90
2. Team B...85
3. Team C...80
4. Team D...75

Team D beats team A and they exchange 3 points
this will make no difference to the positions because all the teams are too far apart

1. Team A...87
2. Team B...85
3. Team C...80
4. Team D...78

However
Example 2

1. Team A...90
2. Team B...77
3. Team C...76
4. Team D...75

Again, team D beats team A and they exchange 3 points
This results in Team D jumping into second.
Team B and Team C drop a place, even though they haven't played

1. Team A...87
2. Team D...78
3. Team B...77
4. Team C...76

This is because, even though the teams are in the same positions in both example, some of the teams are much closer together in points

 

[Dizzy]

great explanation

 

[SavageLez]

I am not sure of the number but there is a "Handicap" for HOME games. So if NZ win at home for example that "handicap" gets subtracted from the points earned in the win before added to the total points. Similarly, if NZ lose at home they will lose more points than if they lose in SA for example (margin of loss also determines the outcome).

If NZ lose this weekend to SA by 15 points or more SA will take over the No.1 spot in the IRB rankings!

Better explained in the site below:
http://www.lassen.co.nz/pagmisc.php?teama=NZL&teamb=SAF#hrh

 

[smartcooky]

I am not sure of the number but there is a "Handicap" for HOME games.

Yes, I already said that. I merely tried to give Dunc a simple example.

However, if you must, the handicap system works by treating home side as if they are three points better than their actual rating. The consequence of this is that they will gain fewer points for winning and lose more points for losing.

Better explained in the site below:
http://www.lassen.co.nz/pagmisc.php?teama=NZL&teamb=SAF#hrh

Actually, Kevin Lassen's site does NOT explain how the ranking system works, it just provides a simple way to enter some data into a mysql query that uses the same algorithm used by the iRB.

Kevin's site also provides a link to here on the iRB website...

http://www.irb.com/rankings/explain/index.html

which is a full explanation of how it works.