Sunday, March 29, 2015

India Vs New Zealand - Second best team at the world cup?

The Cricket World Cup 2015 is finally over and Australia are the champions again. They are certainly the best team in this competition. In fact, knock out tournaments are well designed to find out the best teams in the competition. In fact, it can be shown that a knockout system is the most efficient method to find out which team is the best in a given set assuming the results are transitive.

This format unfortunately is not a good one to find the second best team in a set of teams. For example Australia beat Pakistan, India and New Zealand in that order to win the World Cup. Which means that any one of the 3 teams could have been the second best team after Australia and were just unfortunate to play Australia early in the tournament. However, there is more data from this world cup to play with.

The elaborate round robin group stage before the knock out stages provides more results to play with and apply transitivity. For example, famously India played Pakistan on the second day of the World Cup and India won that encounter. Which means that one of New Zealand or India is the second best team. Unfortunately, since the both India and New Zealand were in different groups and they won all their matches in group stages, data from the group stages does not sort the problem of which is the second best team.

In fact if we try and rank the teams in the knock out stages using world cup data and transitivity this is the only unresolved ranking:

Note: The game where New Zealand beat Australia is ignored because Australia beat them in a game that mattered more.

If New Zealand would have beaten Australia in the final then the transitivity could have accounted for the full ranking. However, now an India Vs New Zealand match is needed to sort this once it for all. This will make the world cup more productive.