The moon ball worked again for Sam Curran in Adelaide on Sunday.

The England all-rounder has had a tricky run since he returned from injury last month, taking only four wickets at an average of 55.75 in five one-day internationals before boarding the flight from Perth.

His economy rate in that time was 7.39.

But Curran was rewarded for returning to his tried and tested in the second ODI against Australia.

With the first ball of a new spell Curran bowled Jack Edwards with that trademark slower ball - this one clocked slower than many spinners at 50mph.

Edwards, head rocking back and arm on his hip, looked like a man frustrated to have been deceived.

He is not the first to be done by Curran's moon ball. It is one of the 28-year-old's most potent weapons.

Data from analysts CricViz suggests he is averaging 17 with deliveries under 90km/h (56mph) in ODIs since the start of 2025, when he developed the delivery. When bowling above 90km/h, he averages 45.16.

The dismissal of Edwards was his fourth moon-ball wicket. India pair Shreyas Iyer and Ishan Kishan and Sri Lanka's Pathum Nissanka have fallen for the trap in the 50-over format.

Curran was clocked bowling as low as 43mph earlier this year. His top speeds - about 83mph - may be modest, but it is the difference, and the deception, that is effective.

Speaking on the For the Love of Cricket podcast this year, Curran said: "You have to be creative. Guys are developing so fast.

"I've worked so hard on trying to keep the arm speed the same and then I've got better at landing the ball at the right length."

The length of the Edwards dismissal - about 2m from the stumps and by the right-hander's toes - was the fullest of all of his moon-ball wickets.

They have all come from deliveries pitched 6m or fuller. Go shorter and the delivery is not as effective.

With the growth of T20 leagues and batters hitting harder and further, bowlers are having to develop new techniques and an effective slower ball to combat them.

Former England pace bowler Steve Harmison, who famously bamboozled Michael Clarke with a 65mph yorker in the 2005 Ashes, said Curran's ability to disguise the delivery is key to its success.

"You can see his release point is a lot further back than [his off-cutter]," he said on TNT Sports.

"With the moon ball, he is just hoping that the batter gets lost in his movement and body shape.

"He holds the ball between his first finger and his thumb, throws the ball in the air and tries to keep the same arm speed, but the ball comes out behind him much slower."

Ironically, it is the lack of speed that kills.

The delivery that fooled Nissanka was slower than all of spinner Rehan Ahmed's previous six balls in the innings during an ODI this year.

"It does get hit, but I feel if a batter knows I can do something a little bit unique, like when you face a mystery spinner, they might have a bit more doubt," said Curran.

Former England fast bowler Tymal Mills, who has played against Curran in The Hundred and the T20 Blast, said the variation is difficult to pick.

"I faced Sam in The Hundred and it's hard to hit," he said.

"You've got to wait for the ball so long. You're expecting the ball to come to you and it's just kind of floating out there.

"The more you bowl it, the more guys will cotton on to it. I'm sure he'll adapt again."

Mills has clocked speeds up to 93mph, but says having a slow ball is crucial for any bowler.

"You need to be evolving, you need to be adapting and you need to be trying to add a new skill because the game changes all the time," he said.

"It goes in cycles and you need to keep going into different tricks that you've got at various different times."

Former England seamer Jade Dernbach, who developed a go-to back-of-the-hand slower ball to much success, agrees.

"You have to have that sort of variety nowadays, the way one-day cricket is going," he said.

"You can't just be a one-trick pony any more. The game is developing so quickly that you have to develop with it on a yearly basis."

With bowlers like Curran continuing to find new ways to innovate, the moon ball is just one more thing for batters to be worried about.

This article is the latest from BBC Sport's Ask Me Anything team.