Otago is hosting Wellington in the resort town and, if recent history is any judge, the side that bats first wins - and wins big.
Three enormous victories were registered by the side batting first in the opening round of the one-day competition.
Central Districts recorded a 217-run win over Canterbury at Pukekura Park after posting a huge total of 405.
Auckland had similar success against Wellington at Eden Park Outer Oval. Its total of 385 for five proved well out of reach of Wellington, which succumbed for a modest 192.
And the Volts started their campaign in bright fashion with the largest win in the history of one-day cricket in New Zealand - a monster 222-run win over Northern Districts at Molyneux Park.
''I just think it was a show of good batsmanship in the three games,'' McCullum said when asked whether it was part of a trend or just a blip.
''Obviously, there are a lot of guys who scored some big runs and there were a lot of big partnerships. If you get big partnerships it puts a lot of pressure on the bowling team.
''I thought the way our top four set the game up was crucial. They paced the innings well in the first 10 overs. Got through the new ball ... and it allowed the middle order to come in and finish the innings off.
''That is the way one-day cricket is meant to be played and we were pleased with the way we went about our work.''
Otago posted a ground-record 335 for seven. Michael Bracewell was the star with 98 from 79 but the entire top four made significant contributions.
McCullum played a very useful hand as well. His 46 from 33 deliveries helped Otago get past 300 and he also took two for 16.
He was part of the Black Caps' 3-2 series win over Pakistan in the UAE and puts his good touch down to playing plenty of cricket.
With regular captain Aaron Redmond returning to Dunedin following the Alexandra game, McCullum gets an other opportunity to captain his province.
''It has been a while since I captained. I think it was probably a couple of years ago ... so it wasn't too long ago.
''I've done it a number of times for Otago and I enjoy the captaincy role and am looking forward to the challenge.''
McCullum will lead a relatively green side. Ryan Duffy replaces Redmond at the top of the order and he will be making his one-day debut.
Josh Finnie and Brad Rodden made their one-day debuts on Saturday, and seamer Sam Blakely is another player still feeling his way at the top level.
That puts extra pressure on the senior players such as McCullum, Derek de Boorder and James McMillan.
Sam Wells had a brilliant game on his return from injury and helped absorb some pressure. He opened with Redmond and the pair put on 76. He also bowled well, taking three for 15.
Wellington has more experience, and the defending champion will be looking to make amends for a terrible beginning.
Black Caps wicketkeeper-batsman Luke Ronchi bolsters the side and, with experienced campaigners like James Franklin, Michael Papps, Brent Arnel and Grant Elliott in the line-up, the Firebirds arguably start as favourite.
''They'll be pretty keen to rectify a few things. They are a good side and they've been putting good performances together in the last wee while, so they'll be strong, McCullum said.
''We have to focus on the things we do well. If we go about our business the way we want to, hopefully the result will take care of itself.''
Ford Trophy
Queenstown, today
Otago: Ryan Duffy, Sam Wells, Michael Bracewell, Derek de Boorder, Nathan McCullum (captain), Iain Robertson, Josh Finnie, Brad Rodden, Sam Blakely, Jacob Duffy, James McMillan, Bradley Scott.
Wellington: James Franklin (captain), Brent Arnel, Tom Blundell, Alecz Day, Grant Elliott, Mark Gillespie, Stephen Murdoch, Michael Papps, Michael Pollard, Luke Ronchi, Malaesaili Tugaga, Luke Woodcock.
