It helps to swing the ball both ways, but if you're a left-arm quick in a world dominated by right-hand batters, you don't have to. Most left-arm swing bowlers only shape the new ball into the right-hander, with their usual angle - across the batter from over the wicket - allowing them to test the outside edge should the odd ball refuse to swing, or swing less than expected.
The away angle, the inswing, and natural variation are enough by themselves to turn the task of facing a new ball delivered by Trent Boult or Mitchell Starc into a hellish test of alignment. If you're a right-hand batter, you'll want to open your stance up to get a clear sighter of the left-armer thundering in from over the wicket. But you can't get too open, because you'll just be throwing your hands at the ball slanting away from you if you don't line it up with your front shoulder. And you can't get too closed-off either, because here comes that inswinger, threatening your front pad and stumps.
Imagine, then, the effect of a left-armer not just angling the ball one way and swinging it in the opposite direction but also getting the odd one to bend the other way. Imagine that this left-armer is doing this while maintaining perfect length, and with enough control over his wrist that he barely ever strays down leg with his inswinger or offers width with his outswinger.
Ball after ball, going one way or the other, at pace, always finishing on top of your stumps or in the corridor outside off.
Arshdeep Singh bowled a spell like this on Sunday night, a spell from hell that transformed the contest between Punjab Kings and Lucknow Super Giants. Until his intervention, there had been nowhere for bowlers to hide in Dharamsala's first match of IPL 2025. The pitch was benign, the boundary only a miscue away. PBKS had hit 16 sixes - the joint second-most in an innings this season - on their way to 236 for 5.
Then Arshdeep, barely needing the pitch at all, took 3 for 10 in three overs of hypnotic new-ball swing. The wickets were of Aiden Markram, Mitchell Marsh and Nicholas Pooran, a top three who, coming into this game, had scored nearly 63% of LSG's runs off the bat this season.
And Arshdeep made a profound impact even before he picked up his first wicket. He forced both Markram and Marsh into hurried blocks to keep out full inswingers. He beat Marsh's outside edge with a jaffa that started outside leg, finished outside off, and forced the keeper to collect the ball over his head. He got Marsh to swing in vain at another awayswinger.
"I think his first over tonight really set the tone for our bowling innings," PBKS head coach Ricky Ponting later said. "It was a fantastic first over. The ball bounced and moved around. So, you know, he's a, he's a star, no doubt about it. And we're very lucky to have him in our team."
Where other formats allow batters to watch the bowler's release and seam orientation and adjust to the second line and defend, this was a T20 chase of close to two runs a ball. It almost forced LSG's batters to commit early and hope.
Marsh had fallen for a golden duck to Arshdeep's awayswinger when these teams last met, on April 1, squaring up and sending a leading edge ballooning to short third. He fell in similar fashion on Sunday, swinging harder this time but miscuing just as badly. A duck of prolonged agony to follow a first-baller.
Three balls later, Markram was gone too, with Arshdeep profiting from the ball stopping on the batter and contributing to a chop-on.
LSG were two down, but their most dangerous batter was in the middle. Arshdeep, therefore, was called on to bowl a third powerplay over for the first time this season.
The over began with a rare half-volley, the outswinger to the left-hander, and Pooran drove it handsomely past mid-off. But no ball is a bad ball if you have the right follow-up: Arshdeep went full again, but corrected his length so it wasn't quite as full as the previous ball, and swerved this one the other way, into the stumps. Pooran swung, looking to go leg side, and missed.
Arshdeep had only bowled 14 balls, and LSG had only faced 26. The match would stretch on for 94 more balls, but the contest was over.
"Yeah, once again, great stuff by the captain to bowl him that third over," Ponting said. "I think once we had the two early wickets and then I think Rishabh [Pant] and Pooran together, I think Shreyas [Iyer] understood how important it was to try and break that partnership early.
"So he gave Arshdeep the third over and, and bang, he knocks Pooran over. And at that stage with Pooran out and them being three down inside the powerplay, it was always going to be hard work for them to get back into the game."
This was the high point of Arshdeep's season, but a performance like this was coming. The two-way swing hasn't always looked as dangerous as it did on Sunday - Arshdeep noted that the low night-time temperatures in Dharamsala may have contributed to more swing being available - but there's usually been enough of it to keep batters on their toes. Of all bowlers to have delivered at least 10 overs in this phase, only one - Sandeep Sharma (6.83) - has a better powerplay economy rate in IPL 2025 than Arshdeep's 7.00.
He now has the wickets to go with the economy too: eight in the powerplay as of Sunday, level with Mohammed Siraj with only Khaleel Ahmed (9) ahead. Overall, Arshdeep has now moved to 16, which puts him third on the Purple Cap leaderboard.
Three more league matches remain for PBKS, two of them in the swing-enabling mountain air of Dharamsala. With Arshdeep in the rhythm he's in, the top orders of Delhi Capitals and Mumbai Indians might have a task on their hands.