S Rajesh, Cricinfo's numbers man has produced an invaluable resource. At the beginning of his article, he poses the standard binary bogeyman designed to keep any criticism of the DRS from threatening its well-being. "The Decision Review System has evoked plenty of controversy in the World Cup so far" Rajesh writes, "but even its strongest critic will agree that the system has helped reduce errors". The fact is that most serious, substantial criticism of the DRS has not advocated a return to an Umpire-only situation. My criticism of DRS (I have added and modified my criticism with every new episode as any observer should), relates to the DRS's inability to handle marginality, its involvement of players, and its gradual shifting of the responsibility for judgment from the Umpire to a disembodied System determined by a very finite and limited set of variables (see the ICC's latest revision to DRS as a case in point).
The statistics rounded up by S Rajesh are revealing. On average 28% of reviews have been successful using DRS in the 2011 World Cup. This includes some cases where the result even upon review has probably been wrong, as the case of Mahela Jayawardene against Canada suggests, and some other cases where the review has resulted in marginal decisions being overturned (Ireland's Alex Cusack against India, Shane Watson against Zimbabwe). It also includes a number of cases in which the reviews have been made more in hope than expectation on account of a team's dire match situation. Batting sides have been decisively more successful (34%) than bowling sides (23%) in getting decisions overturned.
The most telling statistic in DRS has been given short shrift by Rajesh. He contends that the reason that only 5 out of 96 reviews have been for catches, is due to the fact that Hotspot is not available in the World Cup. This is hard to credit, for even with Hotspot, it is doubtful that too many disputed catches (as far as edges go) would occur in an ODI game, in which there are very few bat-pad fielders. Besides, its not as though hotspot has been without controversy, or that it is infallible. The fact that 91 out of 96 disputed decisions have involved LBWs is mainly down to the nature of the LBW law itself. How many of these decisions have been obvious mistakes - missed inside edges, cases where the impact has been outside off stump, or where the ball has been missing off-stump or leg-stump (each of which can be reasonably determined without Hawkeye)?
It turns out, that Umpires make far fewer errors than we imagine. Additionally, to turn one of the favorite tools of the utilitarian cost-benefit-analysis aficionados against them, multiply the time used by the average DRS review by 4 when comparing how much time is used up due to DRS, because thats how long it takes for a decision to be reversed. Then compare this time with the average number of mistakes that Umpires make - 27 in 24 games, and then calculate if the economy of error set up by involving players in reviews is worth it.
Contrary to Rajesh's assertion, his stats suggests a compelling argument to eliminate the involvement of the players, to restore the judgment of the expert Umpire and support it with TV technology, or, better still, with technology custom designed for umpiring and interpreted by another expert Umpire.