Pink ball and day Tests must remain closely linked - Williamson

Kane Williamson, the New Zealand captain, has suggested day-night Tests may need to be viewed as a different format if conditions vary significantly from the day game as New Zealand prepare to host their first pink-ball international next summer against England at Eden Park.

In preparation, New Zealand's domestic teams are playing the current round of Plunket Shield matches under lights this week - the first floodlit first-class cricket in the country - although poor weather is having a significant impact. Williamson, who was part of the inaugural day-night Test against Australia in Adelaide, is a fan of the concept but remains unsure if the red and pink ball behave too differently.

"You can't help but enjoy day-night Tests. Having played in the first one - it was a very cool thing to be a part of," Williamson said ahead of the first Test against South Africa in Dunedin. "At the same time, it's a fine balance with trying to keep the purity and tradition of Test cricket, which I think is very important

"And if you are introducing another dynamic to a format that has relatively been untouched then it's very important that it remains very similar in terms of the day game and the night game within the format. If you are making comparisons and there are ranking systems and a bunch of stats that people enjoy, then if the night format is harder or easier or whatever than the day one then it can be very difficult to make those comparisons with any real substance.

"It's important that they get that right. It's an exciting space to pursue and they are doing it, which I think is great for the game and a lot of people are watching it, but it is important that they get it very closely linked."

In October, when Australia were preparing to play their second day-night Test against Pakistan, Usman Khawaja suggested day-night Tests should be categorised differently.

"I would almost like to make pink-ball, day-night cricket a different sort of format on its own," he said. "That way the players will start accepting it a bit more too, but right now we mix them together. It sort of blurs the lines for bowlers and batsmen because we really haven't worked it out yet. But it's a concept that I believe is really good for the game."

Khawaja went on to score 145 in the Adelaide Test and made no mention of whether he stood by his earlier statements in the aftermath. Now, Williamson has raised the subject again although it is unlikely to have any impact on the status of day-night Tests.

Williamson is hopeful the format will continue to improve particularly with regards to the ball, which was first criticised for visibility issues with the seam and the speed at which it deteriorated but has since held up well in Tests in the Dubai, Adelaide and Brisbane. Although there are some concerns at domestic level, Williamson is confident the issues will continue to be addressed.

"It will be interesting to hear back, what some of the feedback is from the Plunket Shield. Playing in that first pink-ball Test match, we knew there were a few things that needed to be improved on and one of those being the ball. I think they have made a few adjustments on that," he said. "It was a great spectacle to be part of and it was a great crowd every day. There's a lot of room for that innovation in the game."