New Zealand's national provincial rugby championship has often been the guinea pig as far as experimental law variations are concerned.
Some have been very successful and my personal favourites are the law which states you can't kick the ball out on the full from your 22m area if it has been passed back, and the scrum defence remaining five metres back from the set piece.
Both have promoted the attacking side of the game.
Good, too, are the new scrum laws - the scrum is about as good as it has been in ages due to the fact there are fewer re-sets and that the referee often allows the ball to be cleared when it collapses.
The fact that the defending halfback must stay in a more neutral position and away from the opposing No8 and halfback has also promoted a better attack from the set piece.
Some, though, haven't worked, and at the top of the list for me is the new interpretation of the law at the breakdown area.
It's a very difficult one because you want to clean up the game and make it easier to understand while also retaining the competitive nature of the breakdown, which is what rugby is all about. There has to be a contest in that zone.
The debate will continue, but I don't think we're there yet. What I've seen in the Mitre 10 Cup suggests we should return to those applied at Super Rugby and test level.
I don't like the fact there is no longer a real contest for the ball because it's taking positions out of the game such as the fetching element to the play of the openside flanker. I understand that players are being kept on their feet and with their hands out of the ruck, but when you look at it now, we're seeing a lot more fly kicking and hacking of the ball and I think that's actually more dangerous than what we had previously.
Players are getting past the ball and don't want to pick it up so they are kicking it, which is incredibly risky when players' heads are on the ground and halfbacks are going in for the ball.
I also don't like the way that attacking teams are almost guaranteed to get the ball back so they can go into contact quite passively and get away with it.
Looking ahead to Argentina's test against the All Blacks in Buenos Aires on Sunday, I wonder just how much of an advantage it is for the Pumas to be playing at the Estadio Jose Amalfitani given their draw, which is punishing once again.
The All Blacks have wrapped up the Rugby Championship after four tests, and had to leave New Zealand only once - a short trip to Sydney for their opener against the Wallabies.
How different it is for the Pumas, who have been to South Africa, back to Argentina, to New Zealand, Australia, and now back to Argentina again. They never get a favourable draw. For all of New Zealand's incredible form, they do get the rub of the green here, and it's happened three years in a row.
For a better balance to the competition, there needs to be better balance on the fixtures list. Maybe the draw should be reversed every year; for example, the All Blacks starting the competition in Argentina before playing in South Africa and then returning home.
I know Argentina aren't helping themselves this year - they are playing Australia in London, for instance - but there could be a fairer system.
People might roll their eyes at the travel factor, but the Highlanders were shot at the end of Super Rugby. I spoke to a few of them a couple of weeks after - none were feeling great and a few were ill.
Argentina are in the midst of that now and will be feeling very fatigued.