England's repeated doubts about DRS misplaced

Bengaluru: Second Test, fourth day (Visakhapatnam): Zak Crawley is dismissed LBW off Kuldeep Yadav in England’s second innings even though all three stumps were visible. DRS’ ball-tracker shows the ball would have hit the leg-stump.

Third Test, fourth day (Rajkot): Crawley is dismissed LBW off Jasprit Bumrah in England’s second innings though the replays appear to suggest the ball would have missed the stumps upon batter’s review. But DRS upholds the on-field umpire’s decision.   

Fourth Test, fourth day (Ranchi): Joe Root is dismissed LBW off R Ashwin in England’s second innings though in replays, a significant part of the ball appears to have pitched outside leg. DRS says the ball had pitched more “in” than “out”.

That’s one three many unfavourable decisions for an English side to handle. Not that it would have made any difference to the 3-1 series scoreline in India’s favour even if those dismissals had gone the other way. But the visitors kicked up a storm with both skipper Ben Stokes and coach Brendon McCullum weighing in with their views.

After Crawley’s dismissal in Rajkot, Stokes called for the abolition of Umpire’s Call. Following Root’s fall in Ranchi, former England captain Michael Vaughan called for fixing cameras and microphones, besides deputing an ICC official, in the Hawk-Eye truck to prevent host broadcasters from potentially manipulating the technology to favour the home team!       

Such contentious decisions obviously leave teams at the receiving end of such verdicts questioning the reliability of the technology, India included. It’s, however, one thing to question technology but quite another to insinuate doctoring of the system, like Vaughan did. 

By the way, Hawk-Eye Technologies, the company that operates DRS, is a Sony-owned English entity whose services are employed in tennis and football as well. ICC had raised similar concerns as Vaughan has now but after a demonstration of the working of the system, the world governing body was convinced that the dat can’t be tampered with.

Let’s examine each of the three dismissals to find out why they were right, if not accurate, because technology has its own limitations. Remember, technology was introduced to minimise howlers and inconsistencies. For example, an umpire may give two different verdicts in two similar situations based on the analyses that can be highly subjective, but a machine is immune to that.

Illusion of the angle

In the first instance, as Crawley went on the backfoot to play Kuldeep, the opener missed the line as the ball deviated a bit upon pitching and hit his back leg in front of the leg stump. Given the slight deviation after pitching, it’s only fair to assume that the ball would have missed the leg stump, given the distance between the point of impact and the stumps. But that wasn’t the case. 

Here is why. You may have heard the third umpire asking the DRS director to show spin vision after a player referral. The replay that we get to see on TV immediately after a review is from the spin vision camera, which is placed at least three feet away, either to the left or right, from the straight camera. The Hawk-Eye camera is placed right below the straight one. The angle of the manually operated spin vision camera gives us an impression slightly removed from reality. Therefore, as judged by the Hawk-Eye camera, Crawley was more in line with the stumps than it appeared on TV screens.     

You may ask why not show the replay from the straight camera. That is used for wide shots and the clarity is not suitable to assess a referral, challenging the on-field decision. The spin vision camera gives a tighter shot of the ball and inside edges are detected more convincingly, helping the third umpire to arrive at a decision without looking at more evidence like Ultra-edge or ball-tracking.

Change in rules

In the second instance, it was a case of technology not being able to produce a clearer image, but again, it was more out than not out. To know the reason, we must recall the changed DRS rules for LBW decisions.  

In April 2021, the Anil Kumble-headed Cricket Committee of the ICC brought in changes to judge lbws under the DRS. The new protocols, which included the outer perimeter of the bails, effectively increased the area of the stumps a ball must be shown as hitting for a not out decision to be overturned. And if the ball is even brushing the outer limit of a bail, it will be Umpire’s Call upon review. That’s what happened in Crawley’s decision. (see the graphic image). And it was not just Umpire’s Call on line but height as well. It feathered the top edge of the leg bail.

So, in both parameters, line and height, it was Umpire’s Call. It’s just that the imaging wasn’t convincing. An independent study by MIT, commissioned by the ICC, into the accuracy of DRS in 2016 had concluded that there was a 5-10 millimetre margin for error, which was acceptable even for the BCCI, once a staunch non-believer of the ball-tracking technology.      

Line confusion

In the third case, England were befuddled at Root’s dismissal as they were convinced the ball had pitched more out than in line. Paul Hawkins, the founder of Hawk-Eye, came on a podcast to clarify why it was a correct decision. According to Hawkins, every day, the width of the stumps is measured, which then becomes the line between what’s pitched in or out.

Giving the example of how line calls are judged in tennis, Hawkins explained: “You will occasionally get a zero millimetre scenario but tennis have decided that it’s not out until at least it’s one millimetre. So, in tennis we shift the mark, just for presentation purposes, by one millimetre, so a zero millimetre ‘in’ becomes a one millimetre ‘in’ so that you can clearly see the mark. That’s just the presentation thing, nothing wrong with the tracking. It just makes it clearer to the viewer. It would have been clearer on TV (in Root’s case) if the track had come off the ball... You can see the ball clearly over the line. It happens automatically that the ball has pitched outside leg stump. (But) It must be one millimetre more in line than out, because otherwise we wouldn’t have said it has pitched in line. But it’s a very close one. As per the laws, we have given the right answer, but we failed in the ability to not be the story and perhaps there’s a learning opportunity in terms of presentation and stuff to make those very close ones slightly clearer.”  

Why didn't ICC do away with Umpire's Call despite several debates about it at that time?

Anil Kumble had justified the decision to retain Umpire's Call to preserve the role of on-field umpire as the primary decision maker. "The principle underpinning DRS was to correct clear errors in the game whilst ensuring the role of the umpire as the decision maker on the field of play was preserved, bearing in mind the element of prediction involved with the technology. Umpire's Call allows that to happen, which is why it is important it remains."  

How did the BCCI, the staunch opposer of DRS, come around to accept the referral system? 

Kumble, in fact, played a crucial role in BCCI changing its stand on the referral system when he became the coach of the Indian team in 2016. The ICC had under-taken an independent study, the first of its kind, on the reliability of the ball-tracking technology, and Kumble, the then Cricket Committee head of the world body, was convinced by Massachusetts Institute of Technology's evaluation of the system's accuracy. MIT study concluded that the margin of error will be 5-10 millimetres which was acceptable to the BCCI.

How does ball-tracking technology work in cricket?

There are 6-8 cameras depending on the resources of a host nation -- at deep point and deep square-leg, deep cover and deep mid-wicket, and two each on either end behind the bowler. BCCI uses eight cameras for all its international and domestic matches that are telecast. And all these cameras run at 340 frames per second. The first four cameras in line with the popping creases on either end a pitch and used for run-out, no-ball and stumping decisions. The other four (or two as the case maybe) are straight down the line with the middle stump.  To ensure the camera is placed exactly in line with the middle stump, theodolite is used. This instrument helps in placing the camera in the right position and finding out the distance of the camera from the wicket. Then the measurements of the creases are taken. Of course these measurements are standard everywhere, but while marking the lines with paint, there could be some variation, and all these measurements are done in millimeters. These values are then fed into the system. With all the cameras in sync, because all the cameras roll in at the same time, you can pinpoint the trajectory of the ball once it's released, the speed at which it has travelled till it pitches, the speed and the trajectory of the ball after it pitches and height of the impact. After calibrating all this data, the path and height of the ball is predicted in 3D space through triangulation.