So the tour selectors' choice is this: opt for the younger man, who presumably offers a longer prospect, even if his form is ordinary at present; toss a coin; or try something completely different for a one-off situation.
If they are looking at a way, for example, to get Corey Anderson into the XI that might be it. Ideal? Far from it, but he could scarcely do worse. And he could offer a more telling occasional seam option than Jimmy Neesham has so far.
Or the captain, Brendon McCullum, could promote himself on the same stop-gap basis.
It didn't work in the second innings at Port-of-Spain and it shouldn't be done in Barbados either. McCullum is at the heart of the middle order core and should stay there.
To those who believe wicketkeeper BJ Watling is the man for the job, you'll get short shrift from coach Mike Hesson. Watling has been a test opener, but those days are long gone. He does an admirable job at No 7 and his form is good.
Do the two spinners stay for the third test? Put that down to the conditions. Far from being a home sanctuary it was in the halcyon years - 12 successive wins from 1981-93 - the Windies have lost seven and drawn four of 14 tests in Barbados since 2000.
New Zealand's dilemma? Bring back Neil Wagner, giving a genuine third seamer option, and drop either Ish Sodhi or Mark Craig, who battled in Trinidad, or retain the status quo.
Neesham is at present a fourth seamer, not a third. Wagner's hustle and bustle would spark up the attack.
The West Indies have three lefthanders in their top six - Chris Gayle, Darren Bravo and Shiv Chanderpaul - which aids Craig's cause as he turns the ball away from the lefties.
Now add in Kane Williamson, whose offspinners are seen as an occasional, rather than essential, adjunct to the attack. If, however, Williamson was to play a greater role with the ball, that might mitigate against Craig and support legspinner Sodhi's retention.
These are selections New Zealand must get right. Having got themselves in the driver's seat in Jamaica, and eyeing further improvements on the rankings ladder, New Zealand have to give themselves the best opportunity next week.