A review in the penultimate over of the third day's play sparked another debate about the Decision Review System, with Jacques Kallis saying he "is not convinced by the predictive path" of the delivery shown by the ball-tracking technology. Doug Bracewell said members of the New Zealand squad were also "a bit iffy" about the accuracy of the DRS.
The incident under scrutiny was an lbw appeal off Bracewell against Jacques Rudolph which was upheld by the umpire Aleem Dar. After consultation with Kallis, Rudolph asked for a review and the pitch map showed the ball had landed just outside leg stump, resulting in Dar's decision being overturned and Rudolph surviving.
Bracewell was surprised by the decision as, to the naked eye, the ball appeared to have pitched on leg stump. "I thought it was pretty dead. I was going for the inswinger and trying to hit him on the pads and I think everyone thought it was out," Bracewell said. "I think they made a mistake [with the pitch map]. I don't see how the ball swinging back in can pitch outside leg and hit middle stump."
Kallis said he was prompted to persuade Rudolph to seek a review because he had faced Bracewell for most of the day and noticed that he occasionally delivered the ball from a slightly wider position. "I thought the one thing it might have been was that it could have pitched outside leg, coming from that angle," Kallis said. "Fortunately, I was right."
Kallis agreed that in asking for the review he brought to light two major concerns about the DRS. Is there a strategic way to use the system and is it performing its primary function, which is to minimise blatantly incorrect decisions? The answer to both, according to Kallis, is yes.
Because South Africa were in a dominant position at the time of the appeal, Kallis said they were able to ask for a review of a decision they might otherwise have accepted. "We had two reviews and I thought this [Rudolph] is a big batter so with those 50-50 calls I said to him, it's worth a call," Kallis said.
"That system is there to take out the shocker. Maybe with your first review, it's 50-50. Generally captains will say, 'Let's take a risk,' and then the second one you use a lot better. You probably take a little more of risk on that first one."
Kallis also stressed that the main function of the DRS was to eliminate obvious errors, because he remembered playing "in the old time when you got given a bad decision and it can change careers." He said that he "understands" there was a place for a review system, but remained sceptical on its exactness.
"How accurate it is, I don't know. Have decisions improved? I think they have but we have got to accept that there are probably one or two that, as cricketers, we will think 'I'm not so sure', but maybe that's an improvement on absolute shockers which is what you wanted to take out of the game. We are getting that right to a degree but I am not convinced how accurate it really is."
Like many of his Indian counterparts - who have opposed the DRS in its current form - Kallis said what bothers him and his team-mates is the legitimacy of the predictive path, because of height and line.
"Sometimes when it hits the batter and you think that's close and it ends up being a long way away or vice versa. I don't think there are any guys that are 100% sure that that thing is as accurate as they want to make it out to be. They keep saying it but I'm not so sure and I think 99% of cricketers will say that."
On day two, South Africa reviewed an lbw appeal which had been turned down off Imran Tahir against Daniel Vettori. The ball-tracker showed that the delivery would have missed leg stump comfortably, which seemed unrealistic because of the amount of turn on it. "A lot of us looked at Dan's one yesterday and it was closer than what I thought the DRS had it," Kallis said. "It might not have been hitting or it might have been clipping leg, and the right decision was made in the end but [showing that it was] missing leg by that much surprised all of us."
It is instances like these, where the predicted path differs vastly from what is expected that has caused "plenty" of members of the South African team to be concerned about the system. "Sometimes when it hits the batter and you think that's close and it ends up being a long way away or vice versa," Kallis said. "I don't think there are any guys that are 100% sure that that thing is as accurate as they want to make it out to be. They keep saying it but I'm not so sure and I think 99% of cricketers will say that."
South Africa, including Kallis, accept the system as it stands but Kallis said he believes the players should be allowed to speak their minds about the DRS. "We are still allowed our opinion as cricketers and we are still allowed to say how we feel sometimes decisions go."
Kallis also had a suggestion to improve the system. "Maybe what they can do is have the review system that shows where it pitched and where it hits and let the third umpire make the call from there so you still give benefit of the doubt to the batter," he said, stressing that the need for the on-field umpires is still there despite the technology at the game's disposal.
"You don't want to take the umpires' job away but you do want the right decision. The predicted path, for me, is the worry. The Snickometer and Hot Spot and everything else is pretty decent."
Edited by Abhishek Purohit
Firdose Moonda is ESPNcricinfo's South Africa correspondent