Sunday, February 19, 2012

Cricket, anyone?

The cricket season is on with its ups and down, test matches and ODI-s and inflation and deflation of rankings and reputations. Diehard fans, as well as occasional TV watchers wait for Sachin's 100th century, weep for the whitewash in Australia and wonder how things could go so wrong! Let's see what light a bit of quantitative analysis can shed on these events. The ICC rankings, opaque as they are, attempt to quantify the nonquantifiable, the crack of the bat on the ball. A recent paper attempts to do the same, using the techniques of network science, treating the cricket playing nations as a social network. The teams are ranked, depending on their success in test cricket, and one day cricket, for all the years for which the data is available, (1877 onwards, no less), and so are the team captains. The success of a team (or captain) is determined by the ‘quality’ of wins and not on the number of wins alone.

The method consists of forming a weighted network. All competing teams form the nodes of the network. If team A defeats team B, a link is established pointing from B to a A with a thickness (the weight), proportional to the fraction of wins where B wins against A. The importance of the match is assigned via a quantity called the PageRank which uses the normalised weight of the link in a diffusive term which redistributes the credit of a given node to all its neighbours, with maximum credit being transferred to its most successful nemesis. Teams are then ranked by their PageRank, and captains are as successful as their teams.

The results conform to common intuition, which the ICC rankings don't always do. Needless to say, Australia emerges as the strongest test playing nation, followed by South Africa, despite their twenty one year absence from test cricket (1970-1991), England, West Indies, Pakistan, India, Sri Lanka, New Zealand, Zimbabwe and Bangladesh. Since this is an average from 1877, it is unsurprising that this is more or less the order in which the teams started playing test cricket, except for South Africa. For ODI-s, the order is the same, except for Sri Lanka and New Zealand exchanging places. The most successful test captain is Australia's Steve Waugh, followed by South Africa's Graeme Smith, and Australia's Ricky Ponting. From the subcontinent, only M. S. Dhoni and Sourav Ganguly make it to the top 20 list. For ODI-s, Ricky Ponting leads the table, followed by Graeme Smith and Imran Khan of Pakistan. M.S. Dhoni, Kapil Dev, Saurav Ganguly, Mohammed Azharuddin, Rahul Dravid, Javed Miandad, and Wasim Akram also make it to the top 20 list, perhaps indicating that the subcontinent is better at the shorter version of the game. PageRanks computed over successive decades pick up the domainance of the successful teams of those decades, such as the West Indies dominance of both tests and ODI-s from 1981-1990, India's success against strong teams between 1971-1980 (not reflected in the IIC rankings), and the rise and fall of teams like England, Pakistan and Australia in the pecking order. The author (Satyam Mukherjee at Northwestern University, formerly at IIT Madras), modestly says that this scheme cannot replace the ICC ranking, but suggests a novel approach to refine the existing ranking scheme. We hope this scheme will find its way to the cricket commentaries.

This blog post is by Neelima Gupte and Sumathi Rao.

The original paper can be found here .

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