In what is a first in this country, a casino is applying to increase the number pokie machines it has in return for closing down some table games.
SkyCity's Hamilton casino wants to add 60 machines to replace three blackjack tables.
It said this is to satisfy public demand, particularly at busy periods, such as Friday and Saturday nights and public holidays.
SkyCity said the extra 60 pokies would bring the number to 399 and the quid pro quo would reduce the black jack tables from 23 to 20.
This is a test case and SkyCity needs to prove the exchange is proportionate.
SkyCity lawyer Gillian Coumbe QC said the law allows for electronic gaming machines to be substituted for table games.
''We say the commission does not need a statistician to make its assessment and it does not need multiple formulas to make its assessment. The overall assessment is a much simpler, straight forward and common sense one.''
Ms Coumbe said the substitution offers broadly the same player numbers - 60-machines versus 63-seats at the 3-blackjack tables.
She said it is arguably the most straight forward comparison, although comparing the money spent may also interest the commission.
''The relevant consideration is whether you look at the minimum level of wagering, whether you look at the average level of wagering or indeed whether you look at the maximum level of wagering permitted for each of these types of games, you will find that the level of wagering on EGMs is far below that of table games.''
Hamilton casino general manager Michelle Bailey disagreed with comments from some opposed to the licence change that measures put in place to identify problem gamblers is weak.
''I think it is going to help us at those peak times to enable people to have a great customer experience. They will be able to get on to the machines that they want to get on to, which means they will have a great night out. I do not think it is going to increase harm at all.''
She was cross examined by Hamilton City Council lawyer James MacGillivray.
He asked her if SkyCity's application was successful, was it her expectation that there will be more people gambling at the Hamilton Casino than is currently the case.
Ms Bailey replied yes, at the peak times, on the machines.
Mr MacGillivray also asked her if it was her expectation that more money will be wagered on the 60 new EGMs than would be the case in keeping the 3 black jack tables..
A sting operation conducted by Internal Affairs to check on the casino's response to problem gamblers was brought to the attention of SkyCity Auckland's group host responsibility manager, Robert Burrell.
The Hamilton casino failed in some of its responses to help a person, described as a mystery shopper, who was showing signs of being a problem gambler.
Mr Burrell dismissed it as a snap-shot in time which didn't reflect the company's host responsibility.
''If you think of the realities between a mystery shop which is scripted for someone to say something and react a certain way. The reality of problem gambling [is] people don't react in the same way. So mystery shopping is trying to mimic a certain behaviour to get a certain response.''
Michelle Bailey revealed that the Hamilton casino has been trialling facial recognition to help identify people who are excluded from the casino.
The technology is now to be rolled out at each of SkyCity's 4 New Zealand casinos.
''Effectively it enables us to recognise people as they enter, so it is just another tool in our tool kit effectively to help recognise people who are self-excluded. We effectively put in photos of people who have been excluded, into the data base and the camera picks it up.''
The Gambling Commission received 250 written public submissions with the majority against any increase in gaming machines.
The application is also opposed by the Hamilton City Council, the Waikato DHB, Ministry of Health, Salvation Army, Anglican Action and the Problem Gambling Foundation.
They will have their chance to present evidence over the next few days.
Chief Gambling Commissioner Graeme Reeves said the hearing was just to determine a variation to the casino licence and was not in place to stray into irrelevant areas.