McCullum has already adopted an ODI batting mode this summer. In five tests, his 564 runs came at a strike rate of 95.
He'll require the same approach to help his team match public expectations at the tournament.
In 1992, New Zealand morphed from easy-beats to contenders in four weeks. Things are different this time, given how well the team are playing.
There will be instant pressure, despite missing the semifinals of their three most recent international tournaments - two World T20s and the Champions Trophy.
McCullum's had a batting blip at World Cups against top teams.
His record of 414 runs at 31.84 in 18 innings is deceptive. He scored 308 of those against nations ranked outside the top eight, including a century against Canada in 2011. The other 106 came at just 10.60, with his best being 36 not out against the West Indies in 2003.
He doesn't need huge runs but needs them at a fast pace to justify the decision to open with him, even if they're innings of 30s and 40s.
He opened with Martin Guptill in the 2011 World Cup. McCullum's been shuffled through the order since, but the combination is set to rekindle.
McCullum averages more as an opener in 80 innings (33.06) than he does from 36 innings at Nos 3-5 (30.96). If calamity strikes as a result of his aggression, Kane Williamson can repair the innings from No3. Such a plan might also enable Guptill to fulfil an anchor role.
The decision could counter the alarming statistic that, among test-playing nations over the past two years, New Zealand have the worst average ODI opening partnership of 22.35, behind the West Indies' 29.57.
McCullum and Guptill's average stand is 44.16 in 20 outings at a run rate of 5.43, including eight in excess of 50. Even after removing outliers like unbeaten stands of 166 and 72 against Zimbabwe and Kenya and 53 against Canada, the average is 29.65.
McCullum's ODI batting form needs pep.
In 11 ODI innings since the West Indies series started on Boxing Day 2013, his top score has been 51 while averaging 23.40 and striking at 106. To put that in context, several of those scenarios required cameo rather than starring roles, but a couple of solid innings before the World Cup would be welcome.
Previously, despite a formidable record as a wicketkeeper-batsman across all formats, McCullum's failures and frankness used to incite public apoplexy.
Shredding his reputation sometimes morphed into its own sport, despite his longevity racking up a New Zealand-record 92 consecutive tests and the fourth-most ODIs (232).
His glut of runs and the team's most successful year in tests means the public mood has turned in his favour indefinitely.
Comparative instances of such overwhelming national support are few. They can be listed by month since Sir Richard Hadlee's 1990 retirement: February-March 1992 (World Cup semifinalists), July-August 1999 (England test series win), January-February 2002 (ODI tri-series finalists in Australia) and February 2007 (Chappell-Hadlee series whitewash).
Only Imran Khan, with Pakistan in 1992, has led a team to victory in his final World Cup.
With the current tide of goodwill, McCullum can seize the same opportunity at home and immortalise his 13-year international career.
