A Study in Pink - The curious case of the ‘twilight phase’ in day-night Tests

The advent of the day-night Tests in 2015 introduced a few new elements, albeit none more prominent than the ‘twilight phase’.

Published : Dec 04, 2024 17:33 IST , CHENNAI - 4 MINS READ

FILE PHOTO: Lights illuminate the Adelaide Oval as the sun sets during the first night session of the 2015 Test match between Australia and New Zealand. This match, the sport’s first ever day-night Test, saw the “experimental” pink leather ball replace the standard-issue red for the first time in a format that dates back to the 1870s. | Photo Credit: AP Photo/Rick Rycroft

For decades, Test cricket had a template relationship with different times of the day. Swing and bounce early in the day, easier run-making post lunch coupled with a bit more spin and maybe – if conditions permit – a sprinkling of reverse swing in the evening.

The advent of the day-night Tests in 2015 introduced a few new elements into the mix, albeit none more prominent than the ‘twilight phase’.

Over the 22 pink-ball Tests, this twilight period – around half-an-hour or so after sunset – has emerged as the primary hunting window for bowlers.

The day-night Tests have seen wickets fall at an average of 25.16 runs in the third session when the twilight factor usually comes into play. In comparison, since 2015, the third-session bowling average for day Tests is just 30.34.

What makes this more distinct is the jump-off from the second session. In red-ball Tests since 2015, the difference in bowling average from the second session to the third is just 2.84. But in day-night Tests, that number is a massive 5.44.

The numbers are starker in Australia, where delayed sunsets ensure the entirety of the twilight phase lands inside the third session. This, along with the bouncy pitches on offer Down Under, has ensured bowlers have feasted in the third session in day-night Tests.

In the 12 pink-ball Tests in Australia, the third-session bowling average rests at 24.33, which is even better than the corresponding number in the opening session - 24.6.

The same stays true for the bowling strike rate in such games – 47.9 in the third session, and 50.2 in the opening.

This advantage has been best exploited by pacers, who have induced a false-shot percentage of 19.8, the highest across any phase of play, either in red-ball or pink-ball Tests in Australia since 2015.

Many factors have been put forward to explain the pink ball’s added threat in the twilight. The most prominent of them is the visibility factor.

“Anybody who has played with the pink ball will tell you that the roughest period to bat is the twilight period. It is not dark enough for the stadium lights to come on and then have that brightness and daylight isn’t bright enough. So, that’s when it becomes quite challenging for the batters,” said Cheteshwar Pujara in a talk show last month.

Pujara was part of the Indian side which found it difficult to come to terms with the vagaries of the pink ball when it was bowled out for 36 by Australia in Adelaide in 2021. It is to be noted that India’s collapse happened in the morning session, way before the dreaded twilight period set in.

Going into that calamitous Test, India’s then-vice-captain Ajinkya Rahane had made a portentous observation regarding the behaviour of the pink ball.

“The pace of the red ball stays the same throughout the day. With the pink ball, the pace changes completely in those 40-50 minutes [during twilight]. Both off the wicket and in the air,” said Rahane.

READ: AUS vs IND 2nd Test: Have been told where I will bat, says KL Rahul

What heightens this twilight effect is also the make of the pink ball. Unlike the red variant, this one has a polyurethane coating, ensuring the ball retains its shine longer.

Also thrown into the mix is the pink ball’s black seam, which is far more prominent, ensuring that the movement of the surface is pronounced and sustaining.

“In pink ball, you need a little more reaction time. You have to speed up your footwork. The ball skids and comes quickly. So, there is a little less time than red ball. You will have to make some adjustments there,” said Pujara.

The average deviation offered to the pacers by the pink ball offers is consistently higher than its red counterpart across different ball age. This is along with the higher average speed which comes with the pink one.

India’s last experience of encountering the pink ball under fading Australian light came on the first day of the aforementioned Adelaide Test.

Powered by Virat Kohli and Rahane, India nearly navigated through the tumultuous twilight period, before the former was run out, setting off a mini-collapse. The away team scored 126 runs in the third session for the loss of three wickets.

India will bank a lot on this particular experience as it heads into another day-night Test at the Adelaide, starting this Friday.

(All stats have been taken from Cricviz)