Friday, March 9, 2012

Possible errors in the FIFA Women's Ranking

I'm new at this and I still don't have all the details, hence the "possible" in the title. Maybe I just missed something.

First of all, the official PDF explaining the FIFA Women's Ranking has a couple of errors (certain, not possible). I figured them out, then I've applied the formula to compute the December 2011 ranking using the September - December 2011 games. Looking only at the top 100, I get different values for 26 teams, the difference being between 0.36% (Colombia) and 0.05% (England).

Also see the March ranking I've posted earlier today.

27 Oct Mexico - Colombia 1 - 0 a.e.t. (Friendly)

According to FIFA:

http://www.fifa.com/associations/association=mex/ranking/gender=f/index.html
http://www.fifa.com/associations/association=col/ranking/gender=f/index.html

Mexico lost 5 points, while Colombia gained 4. Now, this (teams gaining/losing different amounts of points) only happens in draws. Sure enough, if I replace the 1 - 0 aet with a 0 - 0 result, I get the same points (-5 and 4). Are FIFA using only the result after 90 minutes? Is this my mistake or theirs?

22 Oct Cameroon - Nigeria 2 - 1 AET 4 - 3 PSO (Olympic Football Tournament Women Qualifier)

According to FIFA:

http://www.fifa.com/associations/association=cmr/ranking/gender=f/index.html
http://www.fifa.com/associations/association=nga/ranking/gender=f/index.html

Cameroon gained 24, with Nigeria losing the same amount.

According to the formula, Cameroon should have gained (and Nigeria should have lost): 45 * (0.84 - 0.21015582) = 28 points (rounded down from 28.3429881).

15 Dec Brazil - Denmark 0 - 1 (Friendly)

According to FIFA:

http://www.fifa.com/associations/association=bra/ranking/gender=f/index.html
http://www.fifa.com/associations/association=den/ranking/gender=f/index.html

Brazil lost 10 points, Denmark gained 11. That's wrong. They should have exchanged the same amount of points (11), not different amounts - this only happens in draws.

Looking only at the top 15 of the September ranking:

1. USA - no problems - same points scored in each of the 2 matches.
2. Germany - no problems - same points scored in each of the 4 matches.
3. Brazil - all kinds of problems. See the table - the last column contains my values.


18/12 BRA 2:1 (0:0) DEN Friendly Women 0 0
15/12 BRA 0:1 (0:0) DEN Friendly Women -10 -11
11/12 BRA 4:0 (3:0) CHI Friendly Women -1 0
08/12 BRA 5:1 (1:1) ITA Friendly Women 3 2
27/10 BRA 1:1 a.e.t. (1:1, 1:0) 3:4 PSO CAN Friendly Women -9 -6
25/10 BRA 1:0 (0:0) MEX Friendly Women -1 1
22/10 BRA 0:0 CAN Friendly Women -8 -7
20/10 BRA 2:1 (0:0) CRC Friendly Women -2 -2
18/10 ARG 0:2 (0:2) BRA Friendly Women 0 0


4. Japan - no matches, no problems.
5. Sweden - no problems - same points scored in each of the 3 matches.
6. England - only one match is different by 1 point


23/11 ENG 2:0 (1:0) SRB WCQ -1 -1
27/10 NED 0:0 ENG WCQ -1 0
22/09 ENG 4:0 (2:0) SVN WCQ 0 0

7. France - 2 of the 5 matches are different, but they cancel each other out.


20/11 FRA 5:0 (4:0) MEX FW 3 2
16/11 FRA 8:0 (4:0) URU FW 0 0
26/10 FRA 5:0 (4:0) ISR WCQ 0 0
22/10 WAL 1:4 (1:1) FRA WCQ 1 2
22/09 IRL 1:3 (0:0) FRA WCQ 4 4

8. Korea DPR - no matches, no problems.
9. Canada - 2 of the 7 matches are different. Both against Brazil.


22/11 CAN 2:1 (0:1) SWE FW 15 15
27/10 BRA 1:1 a.e.t. (1:1, 1:0) 3:4 PSO CAN FW 9 6
25/10 COL 1:2 (0:0) CAN FW 0 0
22/10 BRA 0:0 CAN FW 5 6
20/10 CAN 1:0 (0:0) ARG FW 0 0
18/10 CAN 3:1 (1:1) CRC FW 0 0
22/09 USA 3:0 (0:0) CAN FW -4 -4

10. Australia - no matches, no problems.
11. Italy - 1 match of 7 different by 1 point.


18/12 ITA 3:2 (1:1) CHI FW -1 -1
15/12 CHI 0:6 (0:3) ITA FW 2 1
11/12 ITA 2:2 (1:0) DEN FW -1 -1
08/12 BRA 5:1 (1:1) ITA FW -2 -2
23/11 ITA 2:0 (0:0) GRE WCQ -2 -2
19/11 POL 0:5 (0:1) ITA WCQ 7 7
26/10 ITA 2:0 (2:0) RUS WCQ 4 4
22/10 MKD 0:9 (0:6) ITA WCQ 0 0

12. Norway - no problems - same points scored in each of the 3 matches.
13. Netherlands -  1 of the 5 matches different by 1 point.


24/11 NED 2:0 (2:0) CRO WCQ -2 -2
19/11 SVN 0:2 (0:1) NED WCQ 0 0
27/10 NED 0:0 ENG WCQ -1 -2
22/10 CRO 0:3 (0:0) NED WCQ 1 1
21/09 NED 6:0 (1:0) SRB WCQ 2 2

14. Denmark - no problems - same points scored in each of the 8 matches.
15. Iceland - no problems - same points scored in each of the 3 matches.

About me:

Christian, husband, father x 3, programmer, Romanian. Started the blog in March 2007. Quit in April 2018. You can find me on LinkedIn.

4 comments:

  1. This is very weird. I thought wins after Extra Time count as regular wins. E.g. Japan got the points for a 1:0 win against Germany during the WWC and not for the 0:0 draw after 90 minutes.

    I don't know how it works with penalty shoot-outs, but I think Japan got points for a normal draw against the USA in the final of the WWC.

    Maybe their is some hidden confederation factor?

    ReplyDelete
  2. On a slightly different note, there may be a few hundred women's matches added (and some removed) to/from the rankings calculation over the next few weeks or months. Most of these will be older matches, so I don't think they should affect the calculation too much... I'm not sure that FIFA will make any announcements on this, perhaps taking advantage of the fact that the women's ranking is less scrutinised by the media to just slip the results in and hope nobody notices.

    ReplyDelete
  3. Edgar, I have an idea. Maybe FIFA don't update the ranking points after every match, but only when they publish the new rankings?

    E.g. when USA played Sweden in Algarve they used the ranking points of USA and Sweden from the last published rankings.

    ReplyDelete
    Replies
    1. No, I'd get different points for more teams this way. They update the points after each match.

      Delete