Ranking Rules

I can’t believe that so many engrossing things could happen in a cricket test series!! The first interesting thing was about the venue of the third test, i.e. the Brabourne Stadium. It was the first Test match here since 1973. Since then, the Wankhede Stadium was hosting Test matches in Mumbai. Now Wankhede is undergoing a major renovation for the 2011 World Cup. Another interesting thing about Brabourne is that it was built on land reclaimed from the sea.
The other equally fascinating thing about the Test series was the innings of Sehwag. We were praying for him to break Lara’s 400* record of the highest Test score in an innings, but alas he ended up at 293. It is the third highest score by an Indian, the top two scores of 319 and 309 are also with him. That day he also scored the second fastest double ton in the world, missing the fastest by just 15 balls. He also has the 3rd and the 4th fastest double century in his name. That high-octane, breathtaking innings with blistering pace helped India become the No. 1 Test-playing team.
No.1? How? Who decides it? On what basis the rankings are done? These questions were puzzling me. Then I searched for it in Wikipedia. There I found the rules of the ranking system. This is how the ratings or rankings are calculated:
• Each team's rating is equal to its total points scored divided by the total matches and series played.
• A series counts only if played in the last three years.
• Recent matches are given more weight. Series played in the first two years of the three-year limit count half.
• Find the series result:
o Award 1 point to a team for each win
o Award 1/2 point to a team for each draw
o Award 1 bonus point to the team winning the series
o Award 1/2 bonus point to each team if the series is drawn
• Convert the series result to actual ratings points
If the gap between the ratings of the two teams at the commencement of the series is less than 40 points, then the rating points for each team equals:
o (The team's own series result) multiplied by (50 points MORE than the opponent's rating) PLUS
o (The opponent's series result) multiplied by (50 points LESS than the opponent's rating)
If the gap between the ratings of the two teams at the commencement of the series is more than or equal to 40 points, then the ratings points for the stronger team equals:
o (The team's own series result) multiplied by (10 points MORE than the team's own rating) PLUS
o (The opponent's series result) multiplied by (90 points LESS than the team's own rating)
If the gap between the ratings of the two teams at the commencement of the series is more than or equal to 40 points, then the ratings points for the weaker team equals:
o (The team's own series result) multiplied by (90 points MORE than the team's own rating) PLUS
o (The opponent's series result) multiplied by (10 points LESS than the team's own rating)
• Add the ratings points scored by the team to the total ratings points already scored.
• Update the number of matches played by the team through adding one more than the number of games in the series (a two test match series will result in the match count getting incremented by three).
• Divide the new rating points with the updated number of matches to get the final rating.

India is now at the top of the Test rankings with 124 ratings. Bangladesh and West Indies are at the bottom of the table with 13 and 76 ratings respectively.
A similar calculation is for the ODI rankings. India there stands third with 122 rating points, just 8 ratings points behind the no. 1 Australia.
An interesting trivia; Afghanistan is the no.1 Asian country among the Associate members in the ODI rankings.