Wednesday, December 29, 2010

The Marginal Decision Revisited

A year ago, I proposed a modification to the referral system (since known as UDRS). The idea was as follows:
When the players ask for an appeal to review, the first decision the TV Umpire should make, before any technology beyond the action replay becomes available, is whether or not the on-field Umpire was obviously wrong, or whether it was marginal. A marginal decision should stand, even if Hawkeye shows otherwise. The current version of the marginal decision for LBW (when the ball is shown to graze the stumps) is too narrow. The TV Umpire has to have greater discretion.

While the Ashes Test at the Woollongabba exposed the absurdity in the economy of referrals set up by UDRS, three (and i will extend these to four) decisions at Durban and the response to them have brought the issue of the marginal decision to the fore. It is an underestimated issue, because especially in the case of the LBW, it changes the game profoundly. It is not as though the interpretation of the LBW law has not changed at all over the course of recent decades. The interpretation of the law has been different across geographies as well. For example, an entire generation of Indian batsmen were not good players of the sweep shot, because Umpires in India would give LBWs anytime a batsman missed a sweepshot in front of the stumps. This was a special case of the more general rule, that a batsman got very little benefit of doubt if he was playing across the line in front of the stumps. There was a period in cricket when bowlers found it nearly impossible to get LBWs when the batsman was playing forward. The reasoning here was that the ball had too far to travel (somewhere in the range of 6-8 feet from the point of impact) when the batsman was forward. Recently, there has been a period of distinctly more generous LBW decisions (from the bowlers point of view). My theory about this is that the re-emergence of spin bowling due to Warne, Kumble and Muralitharan from 1990 onwards has caused this shift.

Hawkeye and UDRS impose a highly technocratic intepretation of the LBW law, based on a newly manufactured certainty of the Hawkeye prediction of the path of the ball. This prediction has not been subjected to as much scrutiny as it should be, and this is because the ICC is only indirectly responsible for Hawkeye, which remains mainly within the purview of the broadcasters and the companies producing the technology. All these details are swept aside, because of the apparent certainty that the checklist based intepretation of the LBW law provides.

Umpires adjudicate a contest between batsman and bowler, and especially in the case of the LBW, this aspect of the law is important. For example, if a batsman is padding up to a spin bowler as a tactic, then the Umpire is prone to become less and less sympathetic to the batsman's case. This is how it should be. Umpires also adjudicate for bowlers. How many times have we seen Anil Kumble or Shane Warne appeal for LBWs from their sliders which were not given? The bowler knows what he has delivered - there are two reasons why he may not get the LBW - the Umpire isn't reading him, just like the batsman, or the Umpire reads him, but isn't convinced that the ball would have gone on to hit the stumps.

The three LBWs at Durban which went against South Africa would have benefited from the UDRS, provided an initial subjective judgment was made by the TV Umpire about their marginality. In such an event, I think South Africa would have gotten the Ishant Sharma LBW given, provided hotspot showed no inside edge. The deVilliers LBW would have been ruled to be marginal and the on-field decision would have stood provided the TV Umpire was convinced that the ball didn't hit the glove first (the general consensus seems to be that it didn't, I agree with this). I am less certain about what the outcome of the Boucher LBW would have been. Contrary to the general view, I think that ball did come in a little bit. It was a bad leave, and like deVilliers, Boucher was not offering a shot. If I was the Umpire (a totally amateur one), I think I would have asked the on-field Umpire to reverse the decision, because even though Boucher deserved very little benefit of doubt given that he wasn't offering a shot, it didn't look at good on replay as it did in real time, when the fact that Boucher was leaving it played a larger role (and perhaps much larger than was merited) in the decision making.

I would add a 4th interesting LBW decision to this - Hashim Amla's first innings LBW. It was a marginal decision in my view, which of course is viewed very favorably by UDRS afficionados, only because the little green arc of Hawkeye showed the ball heading towards the leg bail. Amla was sweeping, was hit on off-stump, and the ball was turning and bouncing. It was a close decision, which could have easily gone against Harbhajan Singh. I'm sure India would have complained, but it would still have been marginal. The marginal decisions have gone against South Africa in at Durban. Of this I have no doubt.

UDRS, if it must be applied would be far better if the TV Umpire is allowed to first make a subjective judgment, based on just the replay about the marginality of a decision. If the TV Umpire thinks a decision is marginal, and lets the on-field decision stand, then the side asking for the review should not lose one of it's reviews. Unless this is done, UDRS will fail in it's focus on curbing obvious errors. The effort to eliminate subjectivity in Umpiring decisions is futile. Furthermore, in the process, interpretations of laws have shifted imperceptibly. It is this imperceptibility that is the problem.


  1. Kartikeya, if you are not working towards removing the subjectivity in umpiring, then there is no point in using the technology at all. The current UDRS laws mean that an LBW decision will be decided by one umpire and technology. In what you are suggesting, the LBW decisions will be decided by two umpires and technology.

    Instead, I would simply suggest that where the decisions are marginal and the onfield umpire's decision stands, the review asked for by the captain should not be counted as an unsuccessful one. The fact that the technology suggests that the call was so close that they prefer to go with the on-field umpire's call should also suggest that the captain was justified in asking for a review.

    So lets just keep it simpler and not count those reviews as unsuccessful where decisions are marginal. Involving the third umpire's subjectivity also in a decision would not serve any purpose in my opinion. Too many cooks spoil the broth!

  2. There's no way to remove subjectivity out of any human decisions that involve conjecture. Any human judgment must necessarily bear traces of the maker of that judgment. Objective human judgment is a modernist myth.

    I don't think the point is to remove subjectivity, it is to eliminate decisions that are obviously mistakes. In the process the subjectivity is being transferred to Hawkeye or to the Hawkeye-TV Umpire-Ground Umpire-Player combine. What I propose is that the the TV Umpire should have the opportunity to interrupt this on the basis that some decisions are genuinely marginal - with marginality determined independent to the Hawkeye reading.

  3. Eventually, you are proposing to involve the third umpire's subjectivity in addition to the on-field umpire's subjectivity to call one LBW decision.

    In the current UDRS system, technology is used to overrule or ratify a human decision. In the system that you propose, you are first asking another human to ratify a human decision and if he cannot do so, then refer to the technology.

    It is just adding another middleman in this already way too lengthy process. The LBW law is interpreted differently by different people. So I would suggest that we should stick with just one person's interpretation... and that is the on-field umpire.

    If he is challenged, he may use the technology for assistance and then make the final decision. Where he is correct, the challenger loses a review, unless it is a marginal call. Where he is incorrect, the decision is overturned.

    This will also keep the law simpler and more practicable.

  4. The thinking is, one umpire could make an obvious mistake in real time. A TV Umpire will have to be truly dumb to make an obvious mistake after watching replays. Both are experts, unlike the technology which is dumb.

  5. "The thinking is, one umpire could make an obvious mistake in real time."

    If it indeed is an obvious mistake, it will be detected on a review and the on-field umpire will change his decision with the assistance of technology.

    If it is not an obvious mistake but a marginal one, why involve two interpretations? Lets just go with the on-field call...

  6. The question is - how is marginality determined? Currently, Hawkeye determines marginality. That, I think, is too narrow and dumb.

  7. Doesn't that contain the implicit assumption that Hawkeye can in fact model marginality? What about factors that influence the marginality of a decision that have nothing to do with the trajectory of the ball? Such as, whether or not the batsman was offering a shot?

    Besides, it's far from clear that Hawkeye can model the trajectory well.

  8. "It's far from clear that Hawkeye can model the trajectory well."

    That is exactly why I am asking for the margin of error percentage to be increased for the purpose of decision-making.

    I don't think the implicit assumption is that Hawk Eye can model marginality. Hawk Eye is being used only to model the trajectory and since, we are not entirely convinced about its modelling prowess, we are asking for ICC to create a rule to model the marginality.

    And with regards to the batsman not offering a shot, that is a part of the on-field umpire's judgement. Once the technology with its set of error margins gives a certain set of data to the on-field umpire, it comes down to the on-field umpire's judgement again whether or not to reverse the decision taking into consideration such things as whether the batsman offered a shot and his own subjective judgement in this and other regards.

    P.S.: Looks like my previous comment did not get published on the blog. You did reply to it, which means you must have gotten it on your email.

  9. Kartikeya, I don't see why you wouldn't use Hawkeye/etc. as a judge of marginality where relevant, if you are happy to use it to inform the decision at all. Why is the (generally subjective) choice of some level of leeway any worse than the third umpire inserting his own interpretation of LBW into the mix each time? If we are losing part of the distinction between offering a shot or not, then that's a change worth talking about, but it's nothing to do with the level of certainty claimed by the technology.

    On that note, you're right that removing (some of the) subjectivity isn't the point of the UDRS, but it (or something similar) is the point of the 2000 change in the LBW law. Hawkeye and competitors are well designed for the law as it is now written, and while I think it is important to recognise the history of interpretation of the law and what that means, the use of more advanced technology now has to be seen in light of the decision to remove things like "reading" the bowler from LBW judgments. If Hawkeye is letting something in by the back door, it is pretty close to what the MCC and co. tried to invite in the front to start with.

  10. Jonathan,

    Because that should be a decent test for an "obvious error" - an expert umpire should be able to detect it with the naked eye.

  11. But why do you say the umpire should "first make a subjective decision". If that criterion for review actually makes sense, there isn't any need for further review at all.

  12. Precisely :)
    Isn't it the stated goal of UDRS to eliminate obvious errors? Is all this technology needed for that? Yes and No in my view. In some instances there's an inside edge without too much of a deflection which may be detected. The thing is though, that when the situation becomes less obvious, the tools are more likely to err.