You don't usually look at the strike-rate of a batter making his Test debut, but when he is the only man since strike-rate records have been maintained to have scored 4000 first-class runs at a strike-rate of over 80 while maintaining an average of over 50, strike-rate is the first thing you talk about.
Such a high strike-rate tells you a few things. The obvious one is that Shreyas Iyer is a good batter, a dominating batter, but you also wonder if he has bullied some ordinary bowling or filled up his boots on flat decks. You also wonder if he can play the restrained game when a situation or opposition demands it.
That last bit has been answered amply as Iyer has become the first India batter to have scored a century and a half-century on his Test debut. Both the innings came in strife in a line-up that two experienced batters are lacking runs and others lacking experience. Despite all the restraint, he ended up with strike-rates of 61.4 and 52 in a Test that runs have been scored at 43.17. That speaks to the free-flowing nature of his batting.
Iyer's limited-overs internationals and IPL career offer more clues. He can bully spin bowling all right, and good spin bowling at that. So those first-class runs are not to be scoffed at. In fact his main role when he was a lock in the T20I side was to be a spin power-hitter. It showed in how he pounced on the spinners the moment Tim Southee went off with injury, forcing Kyle Jamieson to come back for a spell.
Iyer has had issues against seam bowling even in ODIs, but he is not the only one. It is not the absence of issues but how you overcome them that makes a batter. That's a question that will be properly asked of him at a later date in Test cricket, but on his debut, Iyer has done well against a side whose seamers have taken 14 of the 17 Indian wickets.
The most impressive part of both of Iyer's innings has been his awareness of when to attack. Apart from the first aerial shot that he tried, you can't really say the bowlers forced him to play an attacking shot when he would rather not. That shows the value of first-class experience even though it has been three years since he last played the longer format. It also perhaps shows the lack of accuracy of New Zealand's spin bowlers, who couldn't create enough pressure after the seam bowlers had to be taken off.
"I have been in these situations before as well," Iyer told Star Sports at the end of the day's play. "Not in the Indian team but during my Ranji days, I remember I used to walk in in similar situations. So my mindset was to just play the session and play as many balls as possible. I wasn't thinking way ahead, I was just trying to be in the present and play one ball at a time."
Iyer does average better and strikes slower in the third innings in Ranji Trophy, but more often than not the third innings in Ranji Trophy carry much less pressure. In five-day cricket, third innings can make or break Tests. When asked about batting with restraint here, Iyer said: "It was really tough because Rahul sir [Dravid, the India coach] had told me we need to play as much as possible. To stay till the end, only then we can get to a good total. I decided I will play as many balls as possible and see to it that we get to a good total. I felt that 250-odd runs including the lead would be really good. Fortunately, we got more than that."
When it comes to listening to Dravid, the story is now famous how the first time Dravid saw Iyer was when he hit a six in the last over of a day's play in a four-day match. Some eyebrows would have been similarly raised when you see Iyer in a Test match giving up all his stumps and late-cutting with and against the turn and well before having seen the team out of danger.
Then again, you don't strike at 82 over 4000 runs without taking a risk or two. Risks are subjective, though, and batting is all about managing risk. Apart from that first miscue, you wouldn't really say Iyer's intent involved significant risk. Dravid and Iyer will be talking all about that when they review the Test, but for now Dravid and Virat Kohli have some talking to do: how do you not retain Iyer after this debut, and if you do, who makes way for Kohli?
Sidharth Monga is an assistant editor at ESPNcricinfo