An overview of Tests in 2015:
Note that India and Pakistan jointly top the chart on the basis of win/loss ratio. Only 9 teams appear as Zimbabwe did not play any Tests this year. Note the sudden slide of South Africa and the continuing decline of the West Indies.
Now we see the latest available ICC Test rankings, dated Dec 21 which corresponds to the end of the NZ-SL series. It will not be strictly comparable to the above chart as it includes Tests since August 2012 with greater emphasis on recent Tests:
Now to ODIs, where series between NZ and SL and between Afg and Zim were in progress on Dec 31. The annual overview:
Leaving aside the freak result for Hong Kong, Australia leads with Bangladesh a surprise runner-up. And Afghanistan has quietly slipped past a number of Test teams. Here is the ICC table correct up to Dec 31:
Australia is undeniably No 1 here with India, SA and NZ fighting for second spot. And Afghanistan has now got to the 10th position, ahead of Ireland and Zimbabwe.
T-20 results are pretty meaningless as major teams do not play much of this format. Anyway, I cover it here for the sake of completeness. Annual review:
England was unbeaten in their one series against Pakistan. As the minnows play more matches (usually against teams of similar strength) they have deceptively high win ratios (see PNG and Scotland for example).
Anyway here are the ICC rankings which cover all the matches played this year:
Oman will also be on this table once they have played enough matches (though this is only applicable for T20Is and not ODIs). Here we see Sri Lanka at the top with a very close bunching of WI, Australia and England after that, and still more bunching between SA, Pakistan and India after that.
But past records do not count for much in this format, especially in the first World Cup in 2007 where the winning team had played precisely one T20I before the championship.