Adelaide: The head of the International Cricket Council said on Sunday the referral system for all Test series could undergo further review and that changes could be made.
The system has been debated since its trial introduction in 2008 and subsequent addition as an optional extra for all test series, particularly the element that allows competing teams to choose which decision should be sent to the third umpire for video evidence.
"From the start we've always had a very open mind about the referral system and we are always open to changes that can make the system better," ICC chief executive Haroon Lorgat told Australian Associated Press.
"I can't say what those changes might be, but we are open-minded."
Each team is limited to two incorrect referrals per innings under the system, and players are learning to choose their referrals more wisely to concentrate on obvious umpiring errors rather than marginal calls.
"More and more people are being won over to the system after having seen it or used it," Lorgat said. "There are still a few people who are not supportive of it."
England coach Andy Flower is among those who have advocated a return to the system used during the 2005 ICC "Super Series" between Australia and World XI, in which the responsibility for referrals was placed solely in the hands of the umpires.
But Lorgat said the system was gaining the confidence of players as more learned how to use it, citing the referral by England's Alastair Cook to correct a wrongful dismissal during the Adelaide Ashes Test as an example of its ideal use.
"It is not there to get a wicket when you are struggling to find one, it is there to fix the obvious errors," Lorgat said. "Alastair Cook's referral on the fourth day when he was given out caught behind off his arm was a classic example."
"That's exactly what it is for, and I'm quite confident we are near to the ideal. We will never have it 100 percent right," he added.