The Championship winners will meet the last-placed team in the competition overall, the runner-up plays second to last and so on until the seventh-ranked side is drawn to meet the eighth.
So where does the science come in?
Well, if you're a Championship team who gets an early pick of who you will host, there's two main factors you want to toss up.
History between the unions and quality of the opponent.
Take Manawatu for example. They picked second for their home game at New Zealand Rugby Union headquarters today and coach Jason O'Halloran said they had two teams in mind: Counties-Manukau and Taranaki.
Counties were picked by Harbour - who had the first selection - so Manawatu Rugby Union chief executive John Knowles proudly announced down the phone line that his team would host Taranaki next year.
"We gave a bit of direction to Knowlesy,'' O'Halloran said. "We realised we'd have second pick in the first round so we gave him two options, basically. Funnily enough, one of those was Counties, which got gobbled up by Harbour. So the next option was Taranaki, thinking we will get a pretty good gate; local derby.''
Therein lies the thinking. Pulling a decent crowd in an ITM Cup game is vital for unions throughout the country and local derbies are a great way to drum up fan support.
Local derbies were a popular choice for chief executives today.
Hawke's Bay had the first choice for their away trip to a Premiership side and they selected Bay of Plenty so the sides can reignite the 'Battle of the Bay', while Canterbury chose to host Otago in a traditional southern shoot out.
There were a collection of other obvious choices as Northland chose to travel down the road to meet big brothers Auckland, while Auckland invited Harbour over for a match that will see the `Battle of the Bridge' hostilities resume.
It's a short and sharp process and almost seems over before it began.
Dr Mark Johnston from the school of mathematics, statistics and operations research at Victoria University in Wellington is the man behind the system that dictates who can pick who without ruining the tapestry of the draw and it runs with a remarkable smoothness.
This year marked the first time the crossover selection process was made open to the media and it was certainly interesting to watch.
The obvious next step is to see a player draft of some form in the future.