Similarly, spinners Daniel Vettori and Kane Williamson bowled without sweepers and with four men around the bat. Zimbabwe didn't disappoint for catches; all but one chance was taken.
McCullum says they wanted to assert their advantage: "I didn't have to do much with 495 runs on the board. It was the beauty of having four seamers asking questions. It meant we could keep attacking by bringing guys on for four to six overs at a time.
"We could also bring Dan [Vettori] in, or, where we needed to try something different, Kane [Williamson]."
Williamson came on when Zimbabwe were 100 for six in their second innings after a partnership of 63. It was classic McCullum: gamble when you think the odds are in your favour. He was right. Williamson immediately persuaded Graeme Cremer to gift of a catch to Doug Bracewell.
McCullum now captains New Zealand in the limited overs matches, which John Wright is convinced will work.
"I have every confidence in Brendon leading," Wright said.
"I've been impressed, especially after the decision to make Ross captain last year. Brendon has been outstanding in how he conducted himself. We knew he'd be attacking and that was good."
It's something that won't change as the Black Caps head into a one-day series.
"I'm going to ask the players to be as free as they can when expressing themselves," McCullum said. "I want them to attack but there is a balance to be found because some of the younger guys have to make the step up from provincial to international cricket.
"Things in the team are good with three out of four test wins. We had a tough wins in Bulawayo and Hobart so to play this convincingly after losing the toss then taking 20 wickets in less than 80 overs, well, you can't ask for more than that. But we'll be asked plenty more questions when South Africa arrive."
A more inclusive culture of success is being bred in the New Zealand dressing room. It was reflected in their post-match celebration by going out to the wicket to have a drink and a chant once the crowds had gone. Such camaraderie is vital if they are to progress up the test rankings from eighth in what will be a busy year playing in the West Indies, India, Sri Lanka and South Africa.
Chris Martin was the major beneficiary of McCullum's handling of his bowlers.
That saw Martin force his way into New Zealand's top 10 bowling performances in a test innings.
NZ best bowling
Best bowling figures for New Zealanders in a test:
1 Richard Hadlee, 9 for 52
2 Chris Cairns, 7 for 27
3 Chris Pringle, 7 for 52
4 Simon Doull, 7 for 65
5= Bruce Taylor, 7 for 74
5= Lance Cairns, 7 for 74
7= Daniel Vettori, 7 for 87
7= Stephen Boock, 7 for 87
9 Danny Morrison, 7 for 89
10 Chris Martin, 6 for 26
