The Hattrick National Team Elo Ratings are back. And the ratings have changed a bit. I've decided to change the weight of Qualification matches (from 30 to 40) and Round II World Cup matches (from 40 to 50). This should reduce the impact the friendlies have on the ratings, a suggestion I've often heard.
The Hattrick Elo Ratings are based on the Elo rating system, developed by Dr. Arpad Elo and adapted to international football by Bob Runyan. The system takes into account the type of match, home advantage and goal difference.
These ratings take into account all national team matches for which results could be found in the Hattrick match archives. Ratings tend to converge on a team's true strength relative to its competitors after about 30 matches. Ratings for teams with fewer than 30 matches should be considered provisional and are not included in any historical statistics.
The ratings are updated each friday. Last update of the season is performed exceptionally on monday after the World Cup Final.
| | | RATINGS | | | CHANGES | | | U-20 RATINGS | | | U-20 CHANGES | | | FORMULAS | | | 21559 unique hits since 2005-10-16. |
The ratings are based on the following formulas:
Rn = Ro + K × (W - We)
Rn is the new rating, Ro is the old (pre-match) rating.
K is the weight constant for the tournament played:
- 60 for World Cup finals
- 50 for most of the World Cup matches
- 40 for World Cup qualifiers
- 20 for friendly matches
K is then adjusted for the goal difference in the game. It is increased by half if a game is won by two goals, by 3/4 if a game is won by three goals, and by 3/4 + (N-3)/8 if the game is won by four or more goals, where N is the goal difference.
W is the result of the game (1 for a win, 0.5 for a draw, and 0 for a loss).
We is the expected result (win expectancy),
from the following formula:
We = 1 / (10(-dr/400) + 1)
dr equals the difference in ratings plus 100 points for a team playing at home.
Hattrick is an online football game where you trade players and coach your team in competition with hundreds of thousands of simultaneous opponents from all over the world. Hattrick is owned by Hattrick Ltd and it is mostly developed by ExtraLives AB.
Formulas used to calculate the Elo ratings have been copied from World Football Elo Ratings web site.
If you have any questions concerning these pages please send HT-mail to user jhattara or e-mail to htelo (at) tenerdo.org.