Two of the greatest players in recent times agree on one aspect of the DRS and persistently argue their case on commentary. Shane Warne and Ian Botham have said during the World Cup that in cases where a player review ends in an "umpire's call" verdict, the reviewing team should not lose its review. Their reasoning is that the umpire's call verdict means that the reviewing team was not wrong on the merits of questioning the umpire's decision. This is a popular view that many other commentators and players have agreed with in the seven years of the DRS era.

I will call this the Warne-Botham view for the remainder of this article. I will argue that this view is wrong.

Umpire's call is specific to lbw decisions. The lbw depends on three distinct parameters. For each of these - pitching point, point of impact with batsman's body, and hitting stumps - three outcomes are possible. An lbw review for DRS can therefore return 27 distinct outcomes. Exactly one of these 27 results in an out verdict. Nineteen result in umpire's call verdicts, while seven result in not-out verdicts.

What does an umpire's call verdict mean? The picture below describes it. Essentially, an umpire's call verdict is returned when the evidence suggests that an appeal is too close to be reliably considered out or not out. As the name suggests, in such cases, no confirmation or reversal is possible, and the umpire's original call is allowed to stand.

Graph: Umpire's call decisions Kartikeya Date

Leg-before appeals lie on a continuum from "clearly out" to "clearly not out". Even though umpires can only make one of two decisions - out or not out - it is possible to visualise such a continuum with the following thought experiment. Consider an lbw appeal that looks stone dead. If 100 professional umpires are asked to rule on this appeal, most would say it is out; let's say 99 out of 100 say it is out. In this instance, we can conclude that the one umpire who differs has made a clear mistake.

Similarly, at the other end of the continuum, consider an lbw appeal that looks clearly not out. If a 100 professional umpires are asked to rule on this appeal, 99 would say that it is not out. The one umpire who differs has made a clear mistake. As we move away from the two ends of this continuum towards the middle, the appeals become less clear. In the process, they become close. If such appeals are shown to the 100 professional umpires of our thought experiment, opinion is likely to be increasingly evenly divided.

This distinction between close and clear is crucial. When appeals are considered close by commentators before a decision is made, they mean that there is a good chance that it is out. In our picture, such appeals could lie anywhere from the middle to the right end of the chart. During a review, the meaning changes. During a review, close decisions are distinct from clear decisions.

As the ICC has explained repeatedly over the last seven years, the DRS is designed to reverse clear mistakes, not close decisions. Warne-Botham argue that because an umpire's call verdict means that decisions are close, reviewing teams should not lose reviews in such cases. This means that according to Warne-Botham, teams that use reviews for purposes the ICC did not intend them to be used for should suffer fewer adverse consequences for doing so.

Disputing an umpire's decision was traditionally considered to amount to dissent. DRS has changed that. Players are now legally permitted to request reviews of decisions on the field. This does not mean that they are now in competition with umpires when it comes to umpiring decisions. There is less justification for reviewing close decisions than there is for reviewing clear decisions. Umpires are experts at making decisions. Players are not.

Warne-Botham would probably argue that players often don't know whether the reviews they request are for close or clear decisions. Players who knowingly review a close decision deserve little sympathy. They seek a reversal on a decision they know to be reasonable, a choice that counters the spirit of the DRS. So no matter what the players think about a decision before they review it, there is no reason to treat an umpire's call verdict differently from a clear reversal.

The current system of DRS is already too lenient to the players. A more perfect version of the review would require the players to specify which aspect of the lbw judgment they disagree with - whether they think the ball was missing the stumps, or that it pitched outside leg, or that there was an inside edge, or that the impact was outside the line of the off stump. Players should have to specify one or more of these specific points of disagreement. They should only get a reversal if they are proved correct in their claims. So if a player says that the ball pitched outside leg and was missing the stumps (trying to hedge bets that at least one claim would be true), but the review shows the ball pitching outside leg and hitting the stumps, such a review should not result in a reversal. Currently players are simply able to dispute decisions by saying "I think that decision is wrong." If players are to be allowed to dispute lbw decisions, they should have to specify exactly what part(s) of the decision they disagree with.

The Warne-Botham view of umpire's call depends on conflating the merits of a review and the accuracy, not of the original decision, but of the player's assessment of the original appeal. But it is the original decision which is being reviewed and if it is not shown to be sufficiently wrong, this means that the review had less merit, not more. Warne-Botham have it exactly backwards.

Should umpire's call exist at all? Now that is a whole other argument.