How seam movement authored the Pallekele chapter of Asia Cup

Dimuth Karunaratne checkmarked the technical boxes. He took out a compact stride in line of the ball, presented the full face of the bat, and even made a last-ditch adjustment to cover for the inward seam movement. Taskin Ahmed, however, rendered his manoeuvres an exercise in futility.

Shaheen Afridi castling Rohit Sharma was a lateral inversion of the aforementioned dismissal. The batter, half-forward, organized himself for the full away-angler only for the ball to land on the seam and digress, appreciably enough to beat the inside edge and cannon into the off stump.

Similarities abound between the two wickets, not least that both came off the new ball under humid conditions in Pallekele where monsoon is at its zenith. As per received wisdom, the moisture trapped beneath the surface was creating a fertile ground for seam movement, literally and metaphorically.

The jury is out on the relation of weather to the behaviour of the cricket ball. Academicians have carried out elaborate experiments to debunk the presumption of the seam swelling on contact with moisture, quashing the popular theory that a pronounced seam leads to increased lateral movement on a damp day. Although the research paper published by Rabindra D. Mehta, one of the most credible and comprehensive studies done on the subject, found that ‘the varnish painted on all new balls reacts with moisture to produce a somewhat tacky surface’ which may aid grip and in turn lead to greater backspin being imparted as the ball rolls off the fingers of a speed merchant.

The improved fizz that Mehta refers to could have been a contributing factor to the downfall of Shubman Gill in India’s Asia Cup opener, where drizzle held up the start of play. Haris Rauf cleaned him up with an indecker; the bolt upright seam on release ensuring the ball landed on the thread to veer, much to the chagrin of Gill whose frontfoot was glued to the crease ala Virat Kohli, another drag-on victim.

Given the lack of consensus around meteorological elements having a bearing on the aerodynamics of a cricket ball – cloud cover, ‘heavy atmosphere’ to be precise, is routinely associated with propitious bowling conditions by fans and pundits alike till date despite empirical evidence against any such interconnection, it won’t be a bad idea to take the word of those who have been there and done that, accumulating precious tacit knowledge over the years.

James Anderson writes in his autobiography Bowl. Sleep. Repeat: Inside the World of England’s Greatest-Ever Bowler, ‘It will be more conducive to the art if it rains and then the sun comes out straight after. The rain will create moisture in the ground, then with the sun the moisture will obviously be in the air. It’s like the pot of gold at the end of the rainbow. I feel like that’s when it moves around more.’

Sunlight did tailgate rain in the nascent stage of India’s innings, so going by Anderson’s school of thought elucidates the sharp seam movement Rauf could extract to hoodwink Gill. The fact that Nepal’s Kushal Bhurtel also fell prey to extravagant seam movement, away this time around as Shardul Thakur oriented the seam towards slip, in a match decided by the DLS method points at the emergence of a trend.

Seam movement has been rife in Pallekele during the Asia Cup and batters consistently bowed down to the phenomenon, because seam movement is harder to deal with than swing, according to Cricviz. Against a ball that moves 1.5 degrees or more in the air, batters collectively average 26.70. Albeit, against balls that move off the pitch at least 0.75 degrees, half the threshold for swing, the overall average hovers around 20.

Taskin Ahmed breached Dimuth Karunaratne’s defences.

Intuitively as well, facing seam is more complicated than swing. Mitchell Johnson explains, “From swing bowling, you get an indication from the hand. If the shiny side is on one side and the rough side is on the other, or from the wrist position or as they release, some bowlers swing it pretty early.’’

Seam bowling, on the other hand, is a different kettle of fish, Johnson avers. ‘’If it’s pitching a couple of yards in front of you, you just haven’t got any time to react. If you don’t know which way it’s going to go then that makes it doubly difficult. It’s just reaction time.”

All 10 Indian wickets were picked by Pakistan’s pacers. Afridi, in particular, bowled full in search of swing before dragging his length back upon the realization that a good-length may better exploit the juice in the deck. The tweak worked like a charm for him and his fellow quicks, with half of the Indian team succumbing to good-length deliveries.

Fuller balls deviate less off the pitch. That is, they hit the ground with a smaller vertical component to their velocity, and so are less likely to deviate off the pitch, and do so to a lesser degree. A ball banged into the hard length (8 metres) hits the ground 30 per cent harder than a half-volley (3 metres) and deviates on average about 15 per cent more. This is then exaggerated by the fact that any deviation on pitching will have a greater effect the further the ball travels afterwards. Whether attacking, defending or trying to rotate the strike, the batter is more likely to edge or miss a good-length ball than one on a full length, as mentioned in the book Hitting Against The Spin.

All told, seam movement is predominantly a function of the surface. The pitches at Pallekele and Hambantota have seen a significant departure from the drier, spin-friendly nature that Sri Lanka’s tracks have traditionally been known for. Anurudda Polonowita is credited for the overhaul. He said, “The pitches were slow and low, so I decided to redo all the pitches before the (2011) World Cup. We took a very methodical, scientific approach and managed to prepare pitches that are much better now.’’

Not only was there extra assistance for the fast bowlers in the three Lankan venues built from scratch for the 2011 World Cup, Pallekele and Hambantota included, pacers have also dominated the wicket charts in the 18 innings in Pallekele since the 2019 World Cup, bagging 72 scalps to the spinners’ 58. Safe to say, curator Asitha Wijesinghe has kept the conditions in Pallekele from reverting to type, with seam movement leaving a discernible imprint on the Asia Cup.

Key references: 
https://ntrs.nasa.gov/api/citations/20000112958/downloads/20000112958.pdf

https://wisden.com/stories/features/long-read-the-story-of-the-wobble-seam-the-ball-that-changed-cricket

https://www.espncricinfo.com/story/a-good-test-match-pitch-for-premadasa-curator-624988