In the space of his first two-and-a-half years in international cricket, Mehidy Hasan Miraz has experienced both extremes. He has taken 12-wicket hauls in historic wins over England and West Indies, which occupy the top two slots among Bangladesh bowlers' best match figures in Test cricket. Now, with his 2 for 246 in Hamilton, he also has the most expensive innings figures for a Bangladesh bowler.
Neither extreme has been a one-off, which is a worry. When Mehidy has done well, he has been a match-winner. But when he bowls poorly, there's nowhere to hide, no middle ground.
The difference, of course, comes down to conditions, and Mehidy has certainly struggled on pitches that haven't offered him much. He averages 20.68 at home and 55.28 away, and even at home, when pitches haven't been responsive, he has had little to show for against good batsmen.
Towards the end of Mehidy's spell on the third afternoon in Hamilton, Colin de Grandhomme struck him for three sixes to push him towards more unwanted records. He is now sixth among Test cricket's most expensive innings figures, but it's important to note that other bowlers to have conceded 200-plus runs in an innings include spin greats such as Muttiah Muralitharan, Anil Kumble, Rangana Herath and Saqlain Mushtaq, among others.
Sunil Joshi, Bangladesh's spin bowling coach, said it was natural for a spinner from the subcontinent to struggle in these conditions, and hoped he would learn to adjust more quickly as he gains experience.
"Finger spinners from the sub-continent travel abroad, they have a challenge," Joshi said. "Miraz had an off day on the first day. We knew that he'd come back. I think he bowled well in patches. They batted really well. It is bound to happen. We need to change our mindset about playing Tests in this part of the world.
"It is a very thin line. Most of the western teams will struggle against spin in the subcontinent. It is how you interpret. Challenges are for the bowlers. He is young so he will learn. We have to give him leverage. I am sure he will come out successful."
Joshi said he found nothing wrong with Mehidy's fundamentals, but insisted that he needed to be more disciplined. "I think there's nothing wrong with his technique. It is in the mindset. You have to be disciplined on the first day.
"Taking nothing away from the New Zealand batsmen, but when they travel to subcontinent, we all know how they will struggle against spin. They will adapt to the situation and mindset. Similarly, our spinners have to adapt to the situation."
Mehidy, though, must be alarmed by the way he keeps leaking runs. By dint of his home performances since his breakthrough series against England in 2016, he has become an important cog in Bangladesh's overall scheme of things. But for half the time, he will have to bowl to quality batsmen on flat pitches like this one in Hamilton.
Away from home, he won't find designer surfaces like the ones in Mirpur or Chittagong, where the ball turns, bites, and takes off or keeps low from the second afternoon onwards. It is true that most teams struggle to score runs against him, Shakib Al Hasan and Taijul Islam at these two venues in Bangladesh, but overseas, only Shakib stands out with his disciplined line and length.
The alarm bells should ring loud not just for Mehidy but also for Joshi and the rest of the decision-makers and coaches within Bangladesh's setup. They have now conceded 700 runs on three occasions, all since 2013, and been on the receiving end of four 200-plus opening stands, three of them since 2015.