Source: ICC
Think of the MRF Tyres ICC Rankings as a system for identifying the players who could be selected for an ICC World XI if it was picked today. Take a look at the latest top tens, and you should find that most of the players at the top would be candidates for your current World XI. The rankings have often been described as a measure of form, but this is a simplification. A form ranking would only look at what a player has done in (say) the last year, whereas our rankings take into account a player's entire career - though they put more emphasis on what he or she has done recently.
We use ‘rankings’ to refer to the positions of players in the tables, and ‘ratings’ to refer to their points.
Players have to have appeared in a match within the qualifying period to appear in the lists (normally 12-15 months for Tests, 9 -12 months for T20s and ODIs). For example, Parthiv Patel lost his place in the Indian Test side in 2008 and disappeared from the lists in 2009. But he retained a rating which slowly diminished as he missed matches. He was then picked again 2016 and returned to the rankings. If a player confirms his retirement he is also removed from the list. So, for example, MS Dhoni retired from Tests in 2014 and was removed from the Test rankings - but he remained in the ODI tables. Players are in the rankings as soon as they complete a match. However, we only publish the top 100 players (at most), so it can take several matches for a player to break into that.
Our normal practice is to update the Test rankings after each Test match (usually within 12 hours) and ODI ratings at the end of each ODI series. We generally don’t publish Test rankings if another Test match is currently in progress. However, if there are lots of overlapping Test matches running into each other we try to be more flexible so that the rankings on the website don't get too out of date.
If a batsman does not bat, his rating is unchanged. We don't want the ratings to punish a player when he hasn't done anything wrong (and it would be tough if, for example, rain wiped out an innings causing all the team to lose points). The situation with bowlers is slightly different. If the opposition are bowled out for less than 150, then a bowler who has not bowled is not penalised (conditions obviously suited the other bowlers, and his services weren't needed). But if the opposition makes a big total, then bowlers who don’t bowl in the innings lose points.
Ratings points have a meaning in the same way as traditional averages do. Over 900 points is a supreme achievement. Few players get there, and even fewer stay there for long. 750 plus is normally enough to put a player in the world top ten. 500 plus is a good, solid rating.
The challenge is to find a fair way of rating a keeper. You can't just rate him on catches and stumpings taken, since these are highly dependent on the bowler creating these chances (how many chances did Warne create for Healy, for example?) No accurate details are kept historically on missed chances, and in any case what is a missed chance? So, as with other fielding skills, we won't attempt to produce a rating since we aren't convinced it would be credible.
Nobody does. There is a common misconception that there is an expert panel that sits down to assess the pitch in each match. In fact, all the Ratings calculations are based purely on the information in the scorecard (as you would find published online or in a newspaper). If both teams score 500 in each innings, the computer rates this as a high-scoring match in which run-making was relatively easy, and therefore downgrades the value of runs scored. If both teams score 150, this indicates that runs were at a premium and a player gets greater credit for scoring well in this game.
We have devised an all-rounder index that gives a good indication of who the best all-rounders in the world are in Test and One Day cricket. To obtain the index, simply take the player's batting and bowling points, multiply them together and divide by 1000. So a player with 800 batting and 0 bowling gets an index of zero (because he can't bowl and therefore isn't an all-rounder!), 600 batting/200 bowling gets a rating of 120, and 400 batting/400 bowling points gets a rating of 160. An index of 300 plus is world class. There are far more all-rounders in T20s and ODIs than Tests, but the same names tend to appear high in both lists. Incidentally, this index does omit one important all-rounder skill, namely fielding. There is no satisfactory way of rating fielding skills statistically at present.
Because the ratings take account of the opposition strength, there shouldn't be any obvious advantage to playing against any particular team. Of course that's not to say that certain individuals do seem to play better against certain opposition or on certain types of pitch.