What we have learnt from day-night Tests

There have been results in all eight pink-ball Tests to date and some have come well within five days. Australia beat New Zealand in three days in the format's first outing in Adelaide, where the groundsman left a generous amount of grass to protect the ball, while England's contest against West Indies at Edgbaston also hurtled to a three-day finish as 19 wickets fell on the third day.

The most extreme result, though, was South Africa's two-day thrashing of Zimbabwe, but that can be put down to the gulf in class. At the other end of the spectrum, the Pakistan-West Indies Test in Dubai went deep into the final day, while Pakistan gave Australia a scare in Brisbane when they threatened to chase 490. Even if, as the forecast suggests, time is lost in this Test to weather, there remains every chance of a result.

Since the first match in Adelaide, where there were just three half-centuries, things have settled down a bit (if you remove Zimbabwe's double collapse). Azhar Ali scored an unbeaten 302 against West Indies, while Alastair Cook also batted through the variety of conditions for his 243 against the same side - although that may say more about West Indies' bowling. There have been some outstanding centuries crafted when the lights have been in full play, such as Usman Khawaja's 145 against South Africa, Shaun Marsh's Ashes hundred last December and Asad Shafiq's 137 in Brisbane. The night session can be demanding - and riveting viewing because of it - but even when the new ball has corresponded with the final session, quality batsmen have been able to find a way.

The most significant change to the ball since the first day-night Test has been the colour of the seam. It has gone from green to black after feedback that it became hard to see the seam under the lights.

"Over the few last days, we've seen that perhaps it a little easier to identify the ball and the seam on it now that's black," New Zealand captain Kane Williamson said. "I recall the last time when you could see the seam, getting your bearings if you were square of the wicket - maybe there was a big slash - sometimes it was hard to focus directly on the ball because the lights would shine off the fluorescent pink."

"When you win the toss - bat. If you are in doubt, think about it, then bat. If you have very big doubts, consult a colleague - then bat," WG Grace once said.

In eight day-night Tests to date only one captain has not batted first: Joe Root against Australia in Adelaide. England lost the match, though if his bowlers had pitched the ball up on the first afternoon it may have been different. Still, it appears Grace's old adage holds true. If a side bats well in the first two sessions, and has at least one set batsman when the lights take hold on the first evening, they have a decent chance of getting through that phase.

So far we have seen one out-of-the-box declaration, from Faf du Plessis in Adelaide, when he ended South Africa's first innings nine down on the first evening, although that had as much to do with David Warner being off the field and unable to open. In the end, South Africa couldn't make a new-ball breakthrough.

This may not be a revelation for cricket played after sunset but, in some countries, day-night Test cricket is going to be a test for the fans at the venue. It won't be an issue in a place such as the UAE, but it is late summer now in New Zealand and the evenings are not as balmy as a month ago. You obviously need the shorter daylight hours to allow the lights to have full effect - one of the reasons the day-night Test in England was played mid-August - but that risks a trade-off and the forecast isn't great this week. Even if it's dry, sitting through two hours of night cricket huddled against the chill won't be everyone's idea of fun. Day-night Tests allow matches to be beamed into homes at prime time, but the big PR push has been about getting fans into the ground. Autumnal nights are probably not the answer.