Monday, November 12, 2012

The State Of DRS: November 2012

I have covered the use of the Decision Review System in some depth on this blog over the past 4 years. At the start of the new cricket season, with two major Test series upon us - one featuring DRS, the other not - I have synthesized my current view of DRS in this post. This post is long (5074 words), but I hope it will give you a sense of the state of play. I have also tried to write this as an essay, as opposed to a blog post in an effort to tame some of the immediacy of the blog form. Please read, share, comment as always.


It has been an eventful few months for Umpiring in international cricket.

In the first ODI between England and South Africa , by my count, 2 South Africans who were reprieved because of the design of the communications protocol. First, Hashim Amla would have been out LBW to Samit Patel on 37 had Alistair Cook chosen to request a review. A B de Villiers should also have been out when he was caught off an attempted switch-hit. In de Villiers’s case, England did not have any reviews left at the time.

At Hyderabad, Brendon McCullum left the crease fuming at his misfortune after an inside edge – the kind that is easily missed in real time, escaped Umpire Davis’s attention in New Zealand second innings. With DRS unavailable, it was immediately seen as a problem that came about due to the system’s absence.

In the Lord’s Test, Jacques Kallis was given out caught at the wicket down the leg side when a ball apparently brushed his glove (which was not, at the time, in contact with the bat). The replays seen on the broadcast available to the public did not conclusive show contact between ball and glove, but the ICC told me that Umpire Tucker was able to identify the contact of ball to glove on a close up of one of the replays. The decision was still an Umpiring mistake, as Umpire Tucker seemed to have forgotten Law 6(8) which precluded the decision since Kallis’s hand was off his bat.

Later in the same innings, South Africa had another scare. Given the erroneously successful review against Kallis, England had yet another review in hand. They chose to review an LBW decision against A B de Villiers which was close, but marginal on several counts – the impact was either on off stump, or just outside, there was some doubt about an inside edge, and de Villiers was reasonably forward. It was not, by any means, plumb. Yet, as Michael Atherton observed on commentary, England would review it because it was “close”. The observation promoted no reflection in the commentary box, even though it was one full of former players of vast experience. This was a review which should never have been available to England in the first place, given the mistake in Kallis’s case.

The Decision Review System is the most far reaching change in cricket since the advent of covered wickets. If that change limited the capacity of the conditions to determine the outcome of the game, DRS has been designed to limit the capacity of non-competitor Umpire’s fallibility to determine the outcome of the game. Or so it is claimed. Proponents make the seemingly simple point that using the system produces more correct decisions. I will provisionally agree with this.

Wrong decisions can multiply due to DRS quite easily, as the first ODI between England and South Africa shows. At Lord’s had a couple of pixels (literally) gone England’s way, we would have had two out of South Africa’s top 6 specialist batsmen given out in error, in what turned out to be a relatively modest scoring game.

In this essay, my hope is to show you why it is not quite as simple as the proponents make it sound, and why there is a case for reserving judgment on the system, even if one is convinced that providing assistance to Umpires to limit umpiring mistakes is a good idea. The BCCI’s stand on the DRS (to the extent that it is publicly known) is useful, in so far as it maintains pressure on the ICC to continually review the system. Of far greater long term consequence to cricket is the effect DRS has on Umpires and the way the law is interpreted.

First I introduce DRS, explain what it is, and what it is not. Then I will focus on the LBW law, as 80% of the DRS use is for LBWs. Finally, I shift my focus to the ICC and its role in developing DRS. These posts are a synthesis (albeit not an exhaustive one) of over 70 posts about technology in cricket that I have compiled on this weblog over the last 4 years.


The Decision Review System is best thought of as consisting of two equally important parts – the technologies and the communications protocols. The technologies currently include ball-tracking, heat signatures, noise signatures and video replays. At various points in the history of DRS since 2008, different combinations of these technologies have been made mandatory or optional. The communication protocol determines the shape of the DRS. Who can ask what type of question to whom, and when? These questions are as important, if not more important, than the expensive technologies. When commentators and critics speak of DRS, they often use the term interchangeably the technologies and the system as a whole. This is far from being the case. Furthermore, it has the effect of ignoring the communications protocols as a distinct part of the System.

The ICC’s published description of DRS runs into more than 4000 words, the vast majority of which are spent describing who can as what to whom, when, in what way, how and to what extent these questions may be answered. These communications protocols include standards for the Player Review and the Umpire Review – the two types of decision review currently permitted in cricket. These rules continue to be tweaked. The most recent change pertains to checking for front foot no-balls automatically after every dismissal, and expanding the umpire’s call zone at the pitching point point of impact (thanks to Jonathan for catching this mistake***) for the ball-track.

Most of the criticism about the DRS has to do with the accuracy of the technology. The BCCI has repeatedly stated its opposition to the system based on the fact that it is not convinced about the accuracy of the technology. Sachin Tendulkar has, in his usual enigmatic style, said he wished the system would be “more consistent”. Jacques Kallis and Doug Bracewell have both expressed surprise about some ball-tracking results. Kallis went so far as to assert that most cricketers (99% of them in his words) were unsure about the accuracy of ball-tracking technology. The problems with hotspot, the heat signature based technology, have received less attention but have nevertheless been identified. Hotspot is known to perform less reliably when the glove is involved instead of the bat. It is also known to perform less reliably when the bat speed is especially high (for example, a batsman aiming a square cut at a spinner). Problems with the sound signature technology (often called “snickometer”) are well documented as well. It is often difficult to identify the source of a given sound signature.

In contrast, there has been little attention paid to the communications protocol. The most controversial aspect of the DRS – allowing players to dispute an Umpire’s decision has aroused little criticism. This could be because the population with the greatest voice in matters cricketing is that of the entirely unaccountable quasi-celebrity ex-player-turned-commentator. David Richardson, formerly the ICC’s Manager of Cricket Operations, and now its Chief Executive Officer has made much of the fact that advent of DRS has significantly reduced player dissent (as defined by the ICC’s Code of Conduct). It is surely more reasonable to observe that dissent has been domesticated and legitimized, rather than minimized. If the point of the dissent rule was to get the player to accept the umpire’s decision, whatever he or she may think about its merit, then DRS has not minimized instances of dissent. Given the number of frivolous reviews players ask for (decisions are not reversed 3 times out of 4), player dissent is alive and well, but is performed with official sanction now. But such subtleties, while they may be important, are peripheral to merits of communications protocol itself.

The player’s ability to dispute a decision comes with the severe caveat that the player can get only two such disputations wrong (one in limited overs games) per innings. This economy of error has meant on occasion, that palpable umpiring mistakes go unchecked because reviews were used up in reviewing far more marginal decisions. The communications protocol also does not permit the players to obtain any new information (apart from what the batting partner or close in fielders may say) before requesting a review. This seriously limits the efficiency of the review. The usual reason given for this is that allowing players to look at a decision before requesting a review would take too much time. Perhaps so. The players are, after all, interested parties.

But what of the disinterested party? The third umpire. Like his colleagues on the field, above the fray. There is currently no discretion available to the third Umpire, even in cases where the technology offers nothing conclusive. In such a case the only option currently available to the third Umpire is to confirm the decision on the field, whatever it may be. This is a major shift in the way Umpiring decisions are made. The benefit of doubt no longer goes to the batsman. It now goes to the decision on the field (even if it is a decidedly bold decision against the batsman). The third Umpire, who belongs to the Elite Panel in Test Matches, is used in a purely clerical capacity. The Third Umpire is best described as an auxiliary match manager. His expert judgment is set aside. The Third Umpire also does not have the ability to initiate a review (except for boundary calls), even though he is, by any reasonable assessment, in the best possible position to identify mistakes. If the assistance of technology is considered good enough to correct mistakes, then it is a puzzle as to why it is not considered good enough to identify them in the first place. As it currently stands, the communications protocol limits DRS to correcting decisions only when the players have a problem with them, or when the Umpires on the field are unsure about what decision they should make in the first place. In doing so, it conflates the Umpire’s human fallibility with errors in judgment that are a function of the method of judgment.

Here I want to draw an important distinction.

There are two types of decisions that get reversed in the current DRS. What’s more, the current DRS is not particularly agile about distinguishing between these two types of decisions. I will call these errors and mistakes, and will define them as follows. Errors occur when two different modes of judgment produce two different decisions. Mistakes occur when the same mode of judgment is able to recognize an incorrect decision. For example, if an Umpire makes a decision on the field, and later, on seeing the replay (the normal replay, without simulations of the ball-track or heat signatures or sound), concludes that he should not have ruled the way he did, then he made a mistake on the field (for example, an inside edge in an LBW which he may have missed, or as in Kallis’s case, the important fact that the glove was off the bat when the ball hit it was missed in the first instance, but is evident on the replay and would lead to a reversal). But if the Umpire makes a decision on the field and sees no reason, in his expert judgment, to reverse it upon seeing the replay, but a view of the hotspot or the ball-track shows evidence at odds with his decision, then the Umpire has made an error. As a general rule, it is possible to say errors typically occur in marginal decisions, while mistakes are more obvious.

There is a significant range to the marginality of umpiring decisions in cricket, and that DRS is not particularly sensitive to it. Next, I will build on this idea by focusing on the LBW law in the age of DRS, and try to clarify why the current DRS’s ability to distinguish between errors and mistakes is limited, and in what way this is a problem.


Given the range of marginality in Umpiring decisions (some are obvious and clear, others, less so), there are some decisions in which the “correct” decision will depend on the method of judgment. LBW decisions have consistently been recorded to be involved in the overwhelming majority of player reviews. According to the ICC, in a 12 month period from June 11 2011 - June 11, 2012, DRS was used in 30 Tests and 38 ODIs. 340 player reviews were requested in these 68 games. Of these 80.58% were for LBWs. 57 reviews out of the 340 were "Umpires Call". In the 2011 World Cup, at one point, 88 out of 96, and eventually 164 out of 182 reviews requested by players involved LBW decisions. The case of the LBW brings to the fore another dimension of this marginality. A truly marginal decision is one in which two contradictory decisions (Out and Not Out) are both reasonably equally possible.

LBW decisions are often marginal, and it is the one mode of dismissal in which the concept of the benefit of doubt plays a particularly important role. The law requires two types of judgments from the Umpires – judgments about things that actually happen (where the ball pitched, where it hit the pad, whether or not it hit the bat before it hit the pad), and judgment about things that would have happened (would the ball have hit the stumps had the pad not been in the way), but actually didn’t. These two types of decisions cannot be reached with the same degree of certainty. Taken together, they result in there being plenty of scope for marginality.

DRS curtails this marginality severely to the specifications within the ball tracking system. There is insufficient space here to discuss how the two ICC accredited ball tracking systems work in detail (they are significantly different). I have discussed this here, but the margins of error defined in the system are not, with one exception, due to the technical limits of the system. They have been placed there by the ICC to avoid radical shifts in interpretations of the law. For example, the 2.5m rule that was introduced during the 2011 ODI World Cup was not on account of limitations of the ball tracking system, but because the ICC wanted to adhere to the convention where batsmen would continue to get the benefit of doubt when impact was too far away from the stumps. The ICC has also continued to experiment with other standards in the case of LBWs, such as the “Umpire’s Call” zone at the stumps, and as of this year, a similarly sized zone at the pitching point as well. If a player chooses to review an LBW decision, then the marginal case is immediately reduced to these zones that the ICC has been experimenting with. In the current DRS protocol, the Third Umpire is not allowed to look at an LBW decision on the field, and apply his expert judgment to conclude that the decision does not look obviously wrong. My argument in this post does not depend on the accuracy of ball-tracking. For the purpose of this post, I will assume that ball-tracking is accurate. Given the advances in computer vision research, this is generally a reasonable assumption.

The Umpire’s judgment is effectively subject to verification by a disembodied data processing system that computes results in Cartesian units (for example, missing by 6mm). The human umpire does not process LBW judgments in this way. The Umpire makes a binary choice – either he’s sure it would have gone on to hit, or he’s not sure. There is likely to be significant uniformity in Umpires deciding whether or not a particular case was obviously out, obviously not out, or marginal. One consequence of this understanding of marginality is that if say a 100 professional Umpires were shown a marginal LBW decision, some of them would give it out, while others would give it not out. By definition, both Out and Not Out judgments would be reasonable. In the case of DRS, however marginal the actual appeal may be in cricketing terms, as far as the computation is concerned, there is no marginality. As a result, reasonable Umpiring judgments (correct decisions by any reasonable standard) will necessarily be reversed by DRS.

If the Law is to rely on a definite computed prediction about its path past the pad, then why require the Umpire to make the original judgment at all? If the Umpire’s mode of judgment is to be preserved, then there must be an intermediate step in which the third Umpire reviews the video replay and determines whether or not the on-field decision was obviously wrong, marginal, or obviously right. If it is any of the last two, the Third Umpire should be able to refuse to use the ball-track. Without this intermediate step, Cricket might as well take away the LBW decision from the on-field Umpire.

Obviously, in the case of an inside edge, or in a cases where the ball has pitched outside the width of the stumps – things which actually happen, technical assistance is useful. Such clear mistakes can be easily reviewed without the help of the ball-tracking.

I do not know which would be better. Giving the LBW decision entirely to the ball-track would provide very consistent and definite LBW decisions. But this would be a very differently interpreted and implemented law than the one that has been in place for the last 50 years. Given the way the LBW law is currently written, in order to be logically tenable, any implementation of the LBW law must be able to treat a given marginal case by making the Out and Not Out decision reasonably possible. The DRS, using ball-tracking, does not allow this. The “Umpire’s Call” in the current DRS is not an Umpire’s to make. Its range is pre-determined by the ICC, with the radical result that the benefit of doubt no longer goes to the batsman, but to the decision on the field.

The ICC have consistently said both publicly and in my email exchanges with them that DRS exists to correct “obvious mistakes”. The case of LBW, which constitutes four out of five DRS-enabled decisions in cricket by the ICC’s own records, is one in which makes no effort to define an obvious mistake, let alone have a way to isolate it is made.

The result is that matches and even tournaments have turned on DRS-enabled reversals. The most famous example of this was the2011 World Cup Semi Final, when Sachin Tendulkar benefited from a DRS reversal of a perfectly reasonable LBW decision given against him by Umpire Ian Gould in the 11th over of India’s innings (bowled by Saeed Ajmal). He went on to make 83, and India went on to win. That was a classic LBW decision which should have been an “Umpire’s Call”. It was a marginal decision in which both Out and Not Out would have been reasonable decisions. Even Indian ex-players on commentary thought it looked close. The ball-tracked showed it to be missing by a whisker. A marginal reversal if there ever was one. Yet, it was not the Umpire’s Call which stood in the marginal case, but the ball-track’s call.

In an earlier avatar, technological assistance was used to verify whether the Umpire judged the pitching point and the point of impact correctly, but not to provide a predicted path. This approach, while more defensible than DRS (if the ambition is simply to correct obvious mistakes) produced ridiculous situations in which the TV Umpire could not say anything about situations where even though the ball pitched in line and hit the batsman in line, was sure to miss off stump or leg stump.

The simplest, most effective way to predict obvious mistakes would be to allow an expert – the third umpire, in his full capacity as an expert, to intervene of his own initiative if he sees something obviously wrong with a decision. While the current LBW law implementation using DRS may result in definite and consistent decisions, it does not limit itself to cases which an umpire would consider obviously wrong. If the ICC wishes to continue using ball tracking for LBW decisions, it must use it exclusively, and not require the Umpire to make a decision in the first place.

In the case of LBWs, DRS is, as I have tried to show, a blunt instrument, wielded with a heavy hand. There is a case to be made for letting all LBW decisions to be determined using ball-tracking. But the ICC has not made that case. The ICC’s case is, on the face of it, a cautious one – they want to be able to address obvious mistakes. For this, a method which imposes less collateral damage must surely be possible.

I will now turn my attention to the ICC and its role in devising DRS.

The ICC on DRS

DRS is the ICC’s brainchild. Cricket’s apex body has developed and nurtured the system and is its most enthusiastic champion. The ICC’s Cricket Committee has unanimously recommended DRS for all international cricket in its 2011 and 2012 annual meetings. The Cricket Committee is not constituted by the member nations, unlike the Chief Executives Committee or the Board. Both Ravi Shastri (representing the media on the committee) and Gary Kirsten (representing coaches as he was India’s Head Coach at the time) were members of the committee (pdf, see p.11) in 2010-11 and 2011-12.

Much of the coverage of the ICC’s work on DRS has been focused on these committees, with the highest committee getting most the attention. The Cricket Committee’s work has not been widely questioned. The representative public comment about the Cricket Committee is perhaps Tony Greig’s observation in his 2012 Cowdrey Lecture that the Cricket Committee is made up of a group of “top class current and former players and umpires” who “give so much time to getting things right”.

The Indian journalist Sharda Ugra reported that “Universal DRS” fell at the Board Table in the 2012 ICC Board Meeting, when in fact, nothing resembling “Universal DRS” was ever on the table at this meeting. It was not approved by the ICC’s Chief Executives Committee or Cricket Committee either. Proposals by both these committees were “subject to members ability to finance and obtain the technology” as reported by Ms. Ugra. The Cricket Committee’s report was based on provisional findings according to the ICC’s statement about their meeting, since Edward Rosten of Cambridge University had not completed his review of the accuracy of ball-tracking. Despite the fact that the review was not complete, the CEC felt it was satisfied with the new research. The Cricket Committee itself “re-iterated its view that, depending on the ability to finance the technology, that DRS should be implemented universally in Test and ODI cricket.” It is difficult to see why they did so, if, as they themselves reported, Rosten’s review was not complete, if they thought that independent testing of ball tracking was necessary.

The Cricket Committee’s actions are even more seriously questionable beyond the anomaly established in the previous paragraph. The ICC has accredited two vendors for ball-tracking technology – Hawkeye Innovations based in UK (creators of HawkEye, used in England and the 2011 World Cup), and Animation Research based in New Zealand (creators of VirtualEye or EagleEye, used in Australia). The two companies use different methods to track the path of the ball. They also use human operators to different extents. I have explained this in some detail elsewhere. The two companies were involved in a public dispute of the merits of their respective systems during the 2010-11 Ashes in Australia. In an interview with me, Paul Hawkins of Hawkeye expressed strong confidence that Hawkeye was accurate enough to be used for Umpiring decisions. On the other hand, Ian Taylor of Virtual Eye left a comment on my blog late in 2010 in which he wrote (his comment is worth reading, but is too long to reproduce here in full):

“Technology can have a place to play but we believe we need to be open about the strengths and weaknesses of the various technologies being used and look at how we can combine the best of those to create tools that give everyone confidence in the information we are presenting. Unlike Paul (Hawkins) I would never claim that our predictions are always correct - how could I - just like an umpire our computer is also taking a best guess at what might have happened and, like the umpire, that guess is totally reliant on what the computer has observed.”

Mr. Taylor’s cautious approach is also reflected in his comment earlier this year about allowing Umpires to reverse errors by Virtual Eye and his critical comments last week. The two ICC accredited vendors of ball-tracking technology approach ball-tracking very differently, both technically as well as philosophically.

As the ICC reported, the Edward Rosten presented the Cricket Committee with results of 14 deliveries taken from one series – Australia v South Africa – tests in which the ball-tracker performed very well. As these were from one series, they could only have been from one provider of ball-tracking. Yet, despite the fact that the other provider had not been tested, the ICC’s Cricket Committee “re-iterated its view that, depending on the ability to finance the technology, that DRS should be implemented universally in Test and ODI cricket”. This re-iteration was from the 2011 finding of the same committee. In 2011, as I learnt, the Cricket Committee did not consider any specific examples and gave its unanimous approval after hearing a presentation from one of the two vendors of ball-tracking. Until (and including) Rosten’s research, not a single review of the ball-tracking technology commissioned by ICC has been published. The MCC did conduct tests on Hawkeye at the Winchester school in May 2008, but Paul Hawkins of Hawkeye told me that he wouldn’t want to hang his hat on those results – that it would be very easy for the ball-track to do well in that test and fail in a match situation.

Based on all this, it is accurate and reasonable to conclude that the ICC’s Cricket Committee recommended the use of ball tracking in Umpiring decisions for at least 2 years (beyond early experimental use) without a single completed study of the technology. Edward Rosten has not been commissioned to conduct field tests. Even with Rosten’s study, the ICC’s Cricket Committee does not believe that its findings are essential to forming a view of the accuracy of ball-tracking. If the Cricket Committee thought otherwise, would they have given their approval for both ball-tracking systems, even though, by their own admission, only one had been tested very briefly?

Be that as it may, the accuracy of ball-tracking is not the serious issue with DRS. DRS’s problems are not technical ones, they are cricketing ones. Ball-tracking is perhaps the most intriguingly unique technology at play in DRS. Its effect on cricket began to be felt well before DRS was in use. As David Richardson has pointed out, Umpires were being judged by ball-tracking (and were judging themselves with ball-tracking) long before DRS came to be. The pressure from being second guessed by the beautiful, unambiguous graphic on the broadcast became irresistible. Given its design, it is hard to accept the ICC’s arguments that DRS is designed to eliminate obvious errors, and assist the Umpires in making better decisions. The acrimony caused by Umpiring errors in international matches had to be addressed as an end in itself. DRS’s design consciously curtails the Umpire’s capacity for exercising judgment. Marginality is codified by the ICC and implemented in the ball-track – it is no longer the domain of the Umpire, notwithstanding the oddly named “Umpire’s Call”. The move to involve the players by instituting the player review (without giving the players the opportunity to gather extra information, say from the dressing room) is the obvious way to tame dissent.

This, in my view, is how the situation stands right now. The ICC is convinced by its design of DRS, including the accuracy of ball-tracking, and its Cricket Committee does not believe that independent scrutiny is necessary. This is an unavoidable conclusion, if the facts about 2011 and 2012 Cricket Committee findings, as reported by the ICC itself, are taken seriously. The ICC has felt no need, over 5 years, to question the basic form of DRS – that of allowing players to review Umpiring decisions, which are verified using codified technical standards (a by-product being the so-called “Umpire’s Call”). The system’s most controversial aspect – the Player Review, seems to be the most settled, despite the fact that it is consistently used by players in all circumstances other than ones in which the Umpire is obviously right as opposed to instances where the Umpire is obviously wrong. The BCCI, for whatever reason, has decided oppose this system (this is based on published reports. I have never been able to speak to anybody at BCCI about this. The ICC and even the vendors of ball-tracking have been significantly more forthcoming).

Cricket is not well served by either the ICC or BCCI in this instance. The ICC has introduced a radical change in cricket – a Decision Review System which as I have tried to demonstrate in this series, does not do what the ICC says it wants it to do. The BCCI has opposed it on the most technical of grounds. If anything, the BCCI’s point about financing (as explained by Niranjan Shah in 2011) is a more persuasive criticism of DRS than its fixation with ball-tracking. Each body acts to satisfy the other as is shown by the fact ICC has commissioned Edward Rosten’s review and then ignored it, while the BCCI thinks ball-tracking is not accurate, but won’t go so far as to oppose its use in all cricket on this basis.

As it currently stands, DRS, a system devised to resolve obvious decisions, is, as Michael Atherton brought home to me when I was listening to his commentary in the recent England v South Africa series, most readily used by teams when they think an appeal is close, not obviously out or not out. This is a problem. Worryingly, the ICC does not see it this way.

*** See Jonathan's comment below. His comment was news to me when I read it, because the rule change pertains to the point of impact and not the pitching point. The way the point of impact is determined is a major difference between the two vendors of ball-tracking solutions. The pitching point is always a computed point - it is statistically highly unlikely that the exact moment when the ball first touches the ground will be capture in a frame of the video unless a very high frame rate (typically reserved for super slow motion, showing over a 1000 frames per second) is used - but this is determined with greater certainty as (a) more information is available, and (b) the pitch and the ball are not both in motion at the point of impact.


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  2. The DRS approach seems a bit more cohesive if you ditch the "umpire's call" terminology used by the broadcasters when the protocol says it is to be reported to the umpire as inconclusive. Of course, at least one of the ball-tracking mobs was probably keen to not have the broadcasters use the word inconclusive for the ICC's arbitrary limits.

    Of course, from run outs to the more recent incessant no ball checking, it's pretty clear decisions aren't made in terms of your definition of marginality. That's pretty straight forward, and as you say, the complications are when you through the player's involvement into the mix.

    (BTW, what do you mean by "expanding the umpire’s call zone at the pitching point for the ball-track." Am I not reading the current document?)

    1. On the Umpire's Call point - it is still left to a combination of parameters to determine whether or not the evidence is conclusive. There is no expert judgment involved there. Thats why I think the "Umpire's Call" is not an "Umpire's Call".

  3. That doesn't sound right. Thanks for pointing it out. The expanded zone is at the point of impact, not the pitching point.

    "The margin of uncertainty applicable to the point of impact with the pad has been increased so that it is the same as provided for determining the projected point of impact with the stumps."

  4. Well, I, like all other people in the world, am in support of the DRS but it is beyond my understanding that the why the Indians are against it and do not use it in their series and I think that you should write a post about that why the Indians don't use the DRS while it the very system due to which they won 2011 world cup when Tendulkar was saved from giving lbw(that too is an controversy as the reply showed the ball at a point other than it's real impact).So I think so should write post about that.

  5. I dispute your contention that the ICC has taken away the benefit of the doubt to the batsmen - something that doesn't exist in the laws, by the by, only ex-batsmen, now commentators' heads. The ICC definitions are strongly biased towards the batsmen.

    Any decision on whether the ball was hitting the stumps - as in the Tendulkar non-dismissal for example - is not out if the trajectory shows it missing the stumps, even by as little as a mm. In statistical terms that means a decision is not out if the probability is less than 50%. By contrast, the absolutely out point is somewhere in the range 95-99%.

    It is hard to say if a similar bias exists for pitching and hitting, because as far as I can tell the MCC has no guidelines for what "in line" means for a ball of non-zero size. I emailed them to ask about this and received no response.

    I'm not sure I see the point in your distinction between marginal and obvious decisions. At a practical level, there will always be a grey area between definitely out, uncertain, and definitely not out. If you allow the third umpire to intervene then you get into a meta discussion of what constitutes marginal, particularly when the ball tracking provides such unerring certainty. The implementation of third umpire interventions in Australian domestic cricket has left a sour taste in many player's mouths for precisely this reason.