Mystery solved! How the fourth stump appeared during a DRS review at the SCG
The operators of the Decision Review System (DRS) have admitted that the ‘fourth stump’ that appeared on the screen during a review at the SCG was an error.
In the 12th over of Australia's second innings of the Sydney Test, India appealed for an lbw against Steve Smith. The replays showed a fourth stump, baffling everyone and leading to a controversy. Luckily, the decision-making wasn’t compromised as the ball was missing the stumps.
Speaking to Cricbuzz, Ian Taylor, MD of Virtual Eye, the company that operates the DRS in Australia and New Zealand, admitted that they erred in showing the fourth stump. Taylor said:
"We tracked the ball normally in our tracking system and it showed it missing the stumps. For the DRS the next step is to play the ball track back, superimposed over the 'end on' broadcast TV camera when the 3rd umpire calls for it. At the start of play, we calibrate the two TV cameras at each end of the pitch to ensure they are perfectly aligned when we play our ball track over the live camera. When we did that, before going to air, it was fine and the ball was clearly missing."
He further added on the case of the mysterious fourth stump:
"Just before we were going to replay, the end-on camera lost focus for an instant and when that happens it loses its calibration. It happens a few times during the day but this was the first time it had ever happened between the time we tracked the ball and the time we had to replay it."
Taylor revealed that their operator went through the recalibration programme to realign the camera. He thought he had done it successfully. But as soon as he replayed the video with the track on it, he realised that it hadn't recalibrated correctly because the ball was now clipping the stump rather than missing it.
Taylor was grateful that the error did not lead to a mistake in the decision. He added:
"It was human error on our part. Fortunately, the error was within the 'umpires call' margin so the result stood -- as it should have.”
Mysterious fourth stump sent cricket experts into a tizzy
After a delivery from Ravichandran Ashwin hit Steve Smith’s pads during Australia’s second innings at the SCG, Ashwin requested skipper Ajinkya Rahane to take the review.
To the human eye, it looked like the ball was going down the leg. Hawk-eye, however, showed the ball hitting what appeared like a virtual fourth stump on screen. Shockingly, this mysterious stump was some distance away from the leg stump.
The third umpire stuck to umpire’s call, and Steve Smith survived.
Taking to Twitter, commentator Aakash Chopra sought a clarification from the authorities responsible on the fourth stump controversy. He posted:
India went on to draw the SCG Test, batting out the entire Day 5. They then won the next Test at the Gabba by three wickets and with that, retained the Border-Gavaskar Trophy.