Hot Spot to undergo testing
The company behind Hot Spot will undertake tests to see whether the cameras can be tricked by the use of artificial substances on the edge of the bat. There is a belief among players that Vaseline can reduce the chances of a thin nick showing up, although it has only ever been rumoured that such tactics are used.
Concerns about the effectiveness of Hot Spot came to the fore when VVS Laxman survived a caught-behind appeal on the second day at Trent Bridge. England were convinced there was an edge but Laxman was equally convinced he hadn't hit it. The third umpire said there was a noise but it wasn't clear from where. Michael Vaughan, the former England captain, sparked controversy by tweeting the suggestion of Vaseline and Stuart Broad was later asked and admitted checking the edge of Laxman's bat but finding nothing.
Warren Brennan, the owner of Hot Spot, has previously said the device's accuracy is around 90-95% and can be impacted by such things as bright sunshine and the speed of the bat in the shot. He now says that it is possible that a substance like Vaseline could reduce the technology's effectiveness and tests will be conducted to try to find conclusive results.
"I would imagine that Vaseline would restrict the friction of the ball hitting the bat so if you reduce the friction you are going to reduce the Hot Spot," Brennan told ESPNcricinfo. "That is pure and simple physics. From what I can remember, quite often the outside of the bat has a layer of some sort of coating.
"Now if you put extra layers on the bat that might do the same thing. As long as it is a harder type of surface then you will get the Hot Spot. But if it is a soft, absorbant type of material then that will probably reduce the friction. It might take us a week or even longer to test all possibilities."
The other theory is that bat stickers on the edge of a blade can also help reduce the chances of a Hot Spot showing up - by showing one, long heat signature down the side of the bat - but Brennan said it is likely to work the opposite way and actually increase the visibility of individual marks.
"What I noticed last week when I was at Lord's was these stickers down the side of certain players' bats," he said. "When I looked at it through the cameras it actually looked like a Hot Spot, four or five little white spots. That was quite unusual so it must have be some sort of logo or the sticker. Through the infra-red I could see those spots.
"I just don't know why a manufacturer would put it on the side of the bat that would make it look like a Hot Spot. I had this conversation with the ICC less than a month ago and told them that we are noticing some of these stickers tend to reflect heat a bit like a mirror. The ICC said if that is the case they might have to look changing the regulations so that the side of the bat does not have any advertising, no stickers and no logos. But that is still a work in progress."
There have been a number of occasions when Hot Spot has proved inconclusive in caught-behind decisions. During the Ashes Kevin Pietersen survived at Melbourne, which incensed Ricky Ponting, while at Sydney Ian Bell survived an appeal which Snicko - which isn't used with the DRS - later suggested was out.
Hot Spot has been made a mandatory piece of technology for the DRS system following the ICC's meetings in Hong Kong last month, where it was also decided to make Hawk-Eye optional. The infra-red cameras have shown themselves to be especially effective at proving bat-pad catches and whether a batsman has been hit pad first in an lbw appeal, although in this series DRS is not being used for any leg-before decisions.
Andrew McGlashan and Nagraj Gollapudi are assistant editors at ESPNcricinfo