The pink ball and day-night Tests are here to stay, according to Daniel Vettori, the former New Zealand captain who is now Bangladesh's spin-bowling consultant. Vettori said the game in Eden Gardens could give a glimpse of how Test cricket could, in the future, be played in front of crowds similar to those that attend T20s and ODIs.
"I think pink ball is a big part of Test cricket," Vettori said. "I think you have to appreciate the fact that there's going to be so many people here. You have to acknowledge that. If you can extend the Test match into the nighttime, it brings more and more people into the game. I think it has a big part of the future but has to be balanced with day games.
"It could almost have a T20 or a one-day atmosphere. [Virat] Kohli or Rohit [Sharma] going out to bat is going to feel like a T20. I think there's going to be an atmosphere no player has played in Test-match conditions. I think that brings another element to the game."
Vettori said the most positive aspect of the day-night Test, from a Bangladesh perspective, is how it has excited the team's fast bowlers, who generally have a minor role in home Tests and have struggled abroad. With up to 6mm of grass expected to be left on the surface to help maintain the pink ball, Bangladesh are likely to play three quicks, with Mustafizur Rahman and Al-Amin Hossain likely to come into the XI.
"The four fast bowlers are very excited," Vettori said. "It is a nice thing. Bangladeshi fast bowlers don't get to be excited a lot. I think they are coming to grips with a slightly different ball. It is the SG pink ball. I think most guys have limited experience with the Kookaburra one.
"But I think there's real optimism. There's going to be a big crowd, so for the whole time it is a real joy to play in this first pink-ball Test."
The main challenge, Vettori indicated, would come during twilight, though the period doesn't last for too long in the eastern part of India, where the light fades quickly and the sun sets early in the evening in winter.
"Pink ball plays normal [during the afternoon]," he said. "I think the challenge will be when the Test is under lights. Sunset is quite early here. I think that'll be the time when we see the pink ball come into play. The twilight hour, dusk, is when it seems to do a little bit more, but my experience is only from watching on TV.
"It will be the period of the Test match when tactically teams might do a few different things. The wicket will be pretty good and that last session will be very interesting with the pink ball."
Vettori said he had heard from the Bangladesh players that sighting the ball may be an issue from square of the wicket. "Visibility is fine, but the only anecdotal conversation I have heard is around being a little bit hard to pick up from point and square-leg.
"It will be interesting to find out if slips, gully and umpire is picking it up well. They say there's a small halo effect [around the ball]. We are excited to play rather than think about the negatives."
Bangladesh have had two sessions at the Holkar Stadium in Indore, where the local authorities gave them access to centre-wicket practice. They had one full session under lights there, but it is a different perspective in Kolkata where the light towers are different.
"We have only had one session when it is slightly dark, so tomorrow will be our first full session under dark with lights on," Vettori said. "So far so good. Because the pink ball plays well at this time of the day, it has generally been positive about the Test."
He also acknowledged the limited role for spinners, particularly against an Indian batting line-up that has been dominant against spin. Vettori said the best a spinner could hope for is to bowl economically in the first innings, without thinking too much about wickets. "In the last three or four years, overseas spinners have been put under a lot of pressure [in India]," he said. "It is because of the nature of wickets, expectations that spinners have to do a job, and the Indian batsmen's skills.
"We saw the pressure Mayank [Agarwal] and [Ajinkya] Rahane put our spinners under. There wasn't a lot to do in the good wicket in Indore. It will probably be similar here. The overseas spinners can't look to dominate here like they do back home. They should try to take 2-60 or 2-70 in the first innings, and then see what the second innings presents to you. It is the right way to go about it."