Hotspot has its problems. Warren Brennan, chief executive of BBG Sports (who provide the technology), recently said that "BBG Sports is disappointed at how the Hot Spot performed in the UK during the England vs India series." In a report from November 2011 after the Cape Town Test between South Africa and Australia (96 all out, 47 all out and all that), Brennan also said that Hotspot has had problems with blurring. This problem, as Brennan explains, arises when the player swings quickly. The appeal against Eddie Cowan falls in this category. In July this year, Brennan told Cricinfo that Hotspot's accuracy (about 90-95%) was also affected by whether the impact was on the bat or the glove.
"Things off the glove can be a bit hit and miss... There is padding on the gloves, which is obviously quite soft and other parts of the glove probably have some metal, usually on the side of the fingers. We get different heat impressions from the glove. While the metal can heat up, it'll be quite hot and when the ball strikes the soft part of the glove, it doesn't leave a great heat signature."
Technology has its limits. It is not surprising that within the last 18 months, the use of DRS has generated plenty of controversy. In the first Ashes Test at Brisbane, a clear Umpiring error could not be corrected because the side which suffered from that decision had no reviews left. Earlier in 2010, the Pakistan batsman Azhar Ali failed to refer, what, according to the technological evidence was an umpiring error against him, and was panned for not doing so. In November 2010, in a series where DRS was not used, VVS Laxman was robbed of a great second innings century when he was given out LBW against Daniel Vettori inspite of a palpable inside edge. The Australian captain Ricky Ponting was censured for dissent after he got into an argument with an Umpire about a review (which was available to everyone on the big screen) against Kevin Pietersen. In each of these cases, the evidence was available, but could not be used for various reasons - reasons which DRS did not, or would not necessarily have overcome.
When India toured South Africa, DRS was not in use. This became an issue when a bad decision was made against Zaheer Khan (who was batting) in one of the Tests, and other more marginal decisions went against AB deVilliers and Mark Boucher. A commentator was quick to use the decision against Zaheer, and add the decisions against deVilliers and Bouchers, to build a case for DRS. The commentator was South African. The evidence from the technology that would normally be in play with DRS, has been used by partisan commentators to criticize Umpires, even in marginal cases. This, you would say is merely a case of incompetent commentator, but the evidence does arm the incompetent commentator.
The 2011 World Cup saw the 2.5m rule become an issue. I later learnt that the 2.5m rule had nothing to do with the limitations of ball tracking technology and everything to do with the ICC's desire to preserve accepted and currently prevalent interpretations of the LBW law.
In the same tournament, the DRS also produced a peculiar, but largely ignored situation. M S Dhoni asked for a review after the Umpire had declared leg byes.
In the Semi Final of the World Cup, Sachin Tendulkar got a crucial reprieve when a decidedly marginal decision against him was reversed upon review.
In another (non-DRS) instance of the use of technology, the wrong replay was used to check for a no ball in a Test Match at Barbados.
When Australia were in Sri Lanka in August and September of 2011, a DRS-based LBW decision against Philip Hughes invited the attention of the ICC's premier Umpire because the ball track seemed to be palpably wrong. Umpire Taufel's comments on the matter also exposed the limitations of his understanding of how ball tracking works, which, given his status as the ICC's premier Umpire, is troubling. In the same series, there was also the problem of different pitch mats.
Finally, in Australia's recent loss at Hobart against New Zealand, ball tracking and hotspot appeared to provide contradictory evidence about the location of the pitching point of the ball.
Technology complicates things. The DRS is a complicated issue. It is not merely about the ball-track or hotspot and their limitations, even though these are significant and interesting. It is also about the many crucial decisions that are made by the ICC without which the DRS wouldn't come into being. Here is short list of the aspects of the decision review system that lie outside the limitations of cameras, microphones and computers.
1. The number of reviews per innings.
2. The definition of margin of error at the stumps in the case of the ball track.
3. The 2.5 metre rule (which has been modified multiple times)
4. The communications protocol - the inability of the TV Umpire to initiate a review.
5. The choice of applicable evidence from each technology - Hotspot can provide a more reliable pitching point than ball tracking, but this is not used.
6. The choice of which technologies will be used (in ICC negotiations, compromises have involved discarding ball tracking, and making hotspot mandatory)
The DRS has also had consequences.
It has gotten spinners to believe that it is producing more front foot LBW decisions. Graeme Swann thinks this is the case, even though only 2 of his 40 odd LBW decisions have been properly overturned in his favor upon review. In contrast, LBW decisions against batsmen off his bowling have been unsuccessfully reviewed 16 times. Shane Warne and Anil Kumble have had far more to do with the change in umpires attitudes to front foot LBWs than DRS or Graeme Swann.
It has affected the nature of the marginal decision in cricket, and as Sachin Tendulkar's exemplary case in the World Cup Semi Final shows, defines a truly marginal decision far too narrowly.
By allowing players to dispute umpire's decisions, it has completed the transition from the age of walking to an age of utter ethical agnosticism. It has also changed the nature of dissent in cricket.
The question is not whether or not DRS should be used. It is fairly obvious that some evidentiary assistance from technology is welcome in cricket. The DRS, as it is currently designed and the form in which it is currently advocated every time a decision goes wrong, goes much further - it adopts a deeply unsubtle attitude to the limits of evidence.
Some have asked why BCCI opposes the use of DRS despite India's experience in the Sydney Test of 2008. This question misunderstands what happened at Sydney. This was a Test in which the current Australian captain Michael Clarke stood after edging a ball to first slip! Steve Bucknor (and more than Bucknor, Mark Benson) and his umpiring was, but a small part of that story. There was monkeygate, the catching agreement, Australian behavior. After all, India's captain did not complain about the Umpiring after that game, he said that "Only one team was playing with the spirit of the game. Thats all I can say".
Hotspot and/or ball-tracking both have limits. They will, from time to time provide wrong evidence. At other times, they will be unable to provide conclusive evidence, or will even provide contradictory evidence. Anybody who is seriously interested in technology must surely understand this. Further, in the last 18 months every link in the DRS, has been shown at one time or the other, to be a point at which wrong or at least debatable decisions have been made. Marginal decisions have been reversed, ball track has been obviously wrong, hotspot has provided both false positives and false negatives (batsmen have walked in cases where hotspot showed nothing).
There is a fundamental problem. Cricket is trying to eliminate controversial decisions and Umpiring errors without asking players to take any responsibility. If batsmen walked as a rule (i.e. if it was an accepted and rigorously followed social convention that a batsman who knows he's out should walk), there would, by definition, be fewer Umpiring errors. Using technology is never going to overcome this basic deficit.
Using DRS is not the answer if cricket's problem is the elimination of obvious umpiring errors. The response to this is often that DRS does help address obvious umpiring errors. The point though, is that it does so at great cost. The cost is in the creation of other controversies, in a change in the interpretation of LBW decisions, in the nature of dissent, in a cricketer's understanding of his ethical responsibilities on the field. DRS also does this very inefficiently. Even Tests where it has been used have not been immune to so-called "howlers". But Tests where it has been used have been affected greatly by the reversal of arbitrary decisions, often to dramatic effect (such as Australia being 47 all out).
The obsession with DRS is preventing, or at least interrupting much needed attention that needs to be directed at addressing the basic problem. The problem can be stated as follows. The questions become successively more specific :
How can available technological evidence be used to assist Umpires in decision making? In which areas do Umpires need this help? How should this help be provided to the Umpires? What is the role of the TV Umpire in this process? How can such a process take into account the limitations of available technology? How can this be made affordable?
This questions cannot be answered in sequence, but must be taken up in dialogue. It goes without saying that answers to these questions will be limited until technologies and protocols are tested. But should these tests happen at the highest level of cricket?
Technology in Cricket is a complicated issue. If nothing else, I hope you are willing to accept this. It is not merely a choice between using DRS or not using DRS.