He chose the prudent option, enabling his team to build a defendable total on a wicket in its third use and appearing to slow as the match progressed. McCullum demonstrated his best playing late and working singles to good length deliveries from the spin-laden West Indies attack. That wasn't easy when he must have been tempted to force the pace.
His maturity was noted under the circumstances and made the pivotal difference.
The West Indies struggled to meet the required run rate from the 12th over, a task hindered by New Zealand's fielding. The visitors finished on 108 for eight. Martin Guptill's leap on the long-on boundary to catch Andre Russell will be another of his myriad catches to make the highlights reel as he produced hang-time to rival Steven Adams. Ryder's turn of pace at long-off to pouch Dwayne Bravo was a credible matcher.
Nathan McCullum finished with four for 24 in his 50th match as a result. His lack of pace on the ball meant the visitors forced their shots.
This match was one of just two New Zealand play in the twenty20 format before they head to Bangladesh in March for the World T20. It provided an excellent snapshot of the team's potential.
New Zealand played almost their strongest line-up - the resting of Mitchell McClenaghan the only variation from what would have been a first XI. Adam Milne filled the gap and did the spot justice getting a ball to angle in to catch the edge of Lendl Simmons' bat in his first over, closing in on 150km/h. Milne went for one boundary in his allotment to finish with one for 15. Like Ronchi, a boost to his confidence will have benefitted with the World T20 approaching.
The West Indies opted for a strong spin contingent of Samuel Badree, Sunil Narine and Nikita Miller on a pitch in its third use.
Useful cameos from Guptill (25 off 16), Ryder (22 off 14) and Colin Munro (22 off 12) were cemented by McCullum's early caution, enabling the freeing of the arms in the last six overs.
If there was an area for concern it was the 18 dot balls conceded by New Zealand in the first 10 overs as they struggled to be decisive against the slower bowlers. Munro probably showed the most nous, especially in the 11th over, taking 11 of the 18 runs off Miller's over, including a switch hit through mid-wicket where he made the decision to reverse the shot early.
New Zealand 189-5
West Indies 108-8