No-one is suggesting the DRS is easy to master, but arguably the worst gaffe was reserved for the final test against South Africa. Faf Du Plessis middled a ball onto his pad in the first innings.
Captain Kane Williamson received appalling advice. He would have been better offering the decision to the crowd gladiatorial-style, with a thumbs-up or thumbs-down.
A more coherent system is needed between bowler, wicketkeeper, captain ... and possibly first slip (but not, as witnessed in the Australia-India series, the coaches' box).
After the Dunedin test, it was suggested to coach Mike Hesson that the team had "cocked-up a few DRS decisions".
"You've probably put that quite succinctly," Hesson quipped. "It's something we need to firm up on.
"With the DRS, you do need to take time to gather information. We missed out on one against Pakistan earlier in the summer, when we took half-a-second too long, and there's probably a couple in this series where we let emotion take over."
Hesson's thinking had not wavered after the Hamilton test.
"The system is right, but some of the decision-making hasn't been great. There has been [gambling] at times.
"Sometimes, you take a calculated risk and sometimes, the emotion, generally from the bowler, can sway things.
"The topic has had plenty of discussion, but if you watch most test matches, there are not many [sides] who are particularly good at it. We're just slightly worse than anyone else."
As an example, England might have had an advantage, with captain Alastair Cook often at first slip. That is more in alignment for lbws and caught behinds than Williamson, who tends to be at mid-off or mid-on.
Fielding at first slip also means you gain crucial communication within seconds, rather than striding in from the non-striker's end. Traditional first slip Ross Taylor could be a key to improvement, and wicketkeeper B-J Watling is pivotal for intelligence on edges and gauging whether he was leaning towards off or legside on lbw shouts.
Bowlers, particularly of the pace variety, can be unreliable, because they are off balance in their follow-throughs, when the ball strikes bat or pad.
After New Zealand's first series victory in 31 years over Pakistan, Williamson said he was in favour of taking an "opportunistic approach". That was rewarded, after a Tim Southee lbw shout was given not out, when it struck Younis Khan failing to play a shot outside off stump.
The decision was overruled. New Zealand must work on getting more of those.
Williamson and coach Hesson's meticulous approach brought four test wins in a New Zealand summer for the first time, and to the cusp of a fifth when rain saw play abandoned in Hamilton yesterday.
Playing the DRS percentages better could enhance that record next summer.
