It is a sight for sore eyes. A dirty, raggedy ball, hurled in fast, dipping, moving late and towards the (relatively) shiny side, shutting down some of the heavy scoring in the second half of an ODI innings. A sight that had been legislated out of the game. And before we blame Australia and Cape Town, it is worth a reminder that ODI cricket made reverse swing nearly impossible well before the yellow sandpaper came out in the Newlands Test in 2018.

Cricket has a love-hate relationship with reverse swing. It’s the sport’s guilty pleasure. It loves it when examples show up on the highlights reels. Arguably the most iconic image in ODI cricket is of Wasim Akram hooping it away from right-hand batters from around the wicket in the 1992 World Cup final. It just creates a dramatic sight: a fast bowler running in, the ball leaving the hand straight but beginning to develop a mind of its own past midway through its flight, and then batters protecting their toes or getting their stumps messed up.

Cricket loves reverse swing, but it doesn’t quite like to know what goes into its making. If it could happen magically, cricket would love it. And it doesn’t want to be seen to be providing the prerequisites for reverse swing. In addition to demonising the work required on the ball to achieve reverse, the ICC all but made sure there wouldn’t be any reverse in ODIs by providing for a ball at each end after the 2011 World Cup. The ball just wouldn’t get old enough for reverse.

And then Jasprit Bumrah jogs in in the 36th over in this World Cup and bowls a hard length. It moves so late and against the angle that we think it is seam movement, because he did not bowl a legcutter. It squares Shadab Khan up and takes the off bail. One man in the commentary box, a past master of the art, Waqar Younis, disagrees with everyone and says Bumrah has bowled a reverse-swinging outswinger. The subtlest of deliveries, especially given Bumrah’s natural angle.

In hindsight, the signs were all there. India had clearly seen a dry square in Ahmedabad, began bowling cross-seam with the new ball, kept bouncing the throws in, and even delayed Bumrah’s return, which is usually just after the 25th over. This time Mohammed Siraj got a return spell first and he kept bashing the ball in cross-seam.

The bowlers had to do something. The new ball wasn’t swinging as much as it had earlier in the year. The batters were coming at the new ball with renewed hatred, making this the most brutal World Cup for bowlers in the powerplay: the run rate has been about half a run per over higher in that period in this tournament than in the two before it.

We don’t know why exactly the ball has not swung conventionally in the tournament as a whole, because if it was to do with this particular batch of balls, as some bowlers have suggested, what explains the above-average swing in Delhi, Lucknow and Dharamsala? (And then, in Dharamsala the swing disappeared in the last two matches played there.)

Whatever it was, the teams were smart enough to identify dry squares in certain venues and began working on reverse swing. In Dharamsala, India again brought Siraj back before Bumrah, in the 25th over. The old ball swung again. Mohammed Shami uprooted Mitchell Santner’s off stump with a yorker that the commentator Shane Watson observed looked like it would pitch three balls’ width outside off.

It was not just the wickets Shami took. India conceded just 68 runs in the last 13 overs, though New Zealand had wickets in hand.

New Zealand themselves tried to get the ball “ready” in their next match, in Dharamsala against Australia. The umpires warned Tom Latham against throws bouncing twice. Mitchell Starc got some tail with the old ball later in the day.

In Kolkata came the most glorious use of reverse, fittingly by Pakistan. In the 31st over, Shaheen Shah Afridi went around the wicket and got the ball to straighten against the angle to clean up Bangladesh’s best batter, Mahmudullah, for 56. Once Afridi was done, Mohammad Wasim took over, knocking over three sets of stumps in seven balls. Bangladesh went from 130 for 4 to 204 all out.

Revere swing is a complex subject. Those who know the science of it will seek to differentiate between what Bumrah and Shami did and what Wasim did. Bumrah and Shami bowled with an upright seam, with hardly any change from the way they release the ball for their “regular” deliveries. This technically might just be contrast swing. What Wasim did was more classic reverse swing: seam tilted in the direction he wanted the ball to swing, a slightly slingy action, and more spectacular results - bigger swing, fuller lengths, stumps flying all over. No wonder he has drawn the most old-ball swing this tournament.

For the purpose of this article, let’s call all old-ball swing reverse swing. Cricketers certainly seem to do so, except for some like Sunil Gavaskar, who make it a point to differentiate between contrast and reverse swing. There is another complication, though. When you do get old-ball swing off hard lengths, like Bumrah did against Shadab, it starts to go so close to the time it pitches that it is recorded as movement off the pitch. That can also sometimes be confused with the old ball gripping off a dry pitch.

At any rate, a trend has been observed in this World Cup: the median swing flatlines in the middle overs and then goes up towards the end. At two or three venues, the old ball has done enough to affect the median swing numbers for the whole tournament. As a whole, the median old-ball swing in this tournament has been less than in other ODIs in India since 2021, but there has been a clear spike in swing towards the end of the innings, suggesting it was conventional swing on display in those other ODIs and reverse in the World Cup now.

One of the reasons could be that in these times of climate change, we are only ending India’s summer now. Some of these venues - Mumbai and Ahmedabad, for example - get a second summer in October anyway. That has possibly left the squares dry, unlike when matches are played early in the year in India. Teams have been smart to realise this and have worked on preparing the ball for reverse.

One of the great things about this game is that the bowlers do find a way. Looking at what Pakistan managed in Kolkata against Bangladesh, reverse should be a factor in the marquee clash between India and South Africa there. If South Africa bat first and manage to set up a platform, a possibly reversing ball from India against the most destructive lower middle order (when they bat first) will be a mouth-watering contest.

It will be a sight for sore eyes, but the umpires will be minding the number of times throws bounce. –Cricinfo