The renaissance continues: he has added new dimensions to his bowling, he has been more confident, and he has been producing match-winning spells. Kuldeep Yadav had wrecked his former team Kolkata Knight Riders earlier in the season, and on Thursday he did it again, finishing with superb figures of 4 for 14 in three overs to restrict them to 146.
He continues to show why he deserves to be part of India's T20 World Cup plans, putting his success down to him becoming "mentally strong" and having "clearer plans".
"I have probably become a better bowler [than before]," Kuldeep told host broadcaster Star Sports after the match. "However, one thing is certain that I have become a lot stronger mentally. When you fail in life, you think, 'Where can I improve?' You learn from your mistakes when you face failure in life. I have worked on it, and now I have no fear of failure."
Kuldeep picked up his second four-wicket haul of this season, taking his tally to 17 wickets. In his first over, he had debutant Baba Indrajith caught at long-on, before trapping Sunil Narine lbw with the very next ball. He came back in the 14th over to dismiss Shreyas Iyer and then set up Andre Russell to get him out for a three-ball duck.
"I liked the wicket of Russell because I set him up well," he said. "I first went around the wicket and then returned to bowl over the wicket. Then I went back to bowl around the wicket and bowled a bit wider. That was my plan. He played out two dots, and then I knew he would step out for a shot. So I perfectly planned for that, and it [the wicket] was an important wicket for us."
This kind of planning - without overthinking - is what has led to Kuldeep having his "best IPL season yet". He was not too worried when he went wicketless while conceding 40 in three overs in the last match against Rajasthan Royals. But that has not always hasn't been the case, he admitted.
Until IPL 2019, Kuldeep was Knight Riders' go-to wicket-taker, averaging 19.43 with an economy rate of 7.32. In 2020, he picked one wicket in five games and was eventually dropped. Kuldeep didn't make the Knight Riders' starting XI in the first half of the 2021 season either, and was then sidelined with a knee injury for the second.
Worrying about giving away too many runs is no longer an issue this time around because he has always found ways to come back.
"I'm enjoying bowling, and I've become a lot clearer with my plans," Kuldeep said. "I don't think too much about what the batter will do, I have also given away some runs. I've backed my skill. I've stuck to my lengths too, though it's not always been perfect.
"But that's what happens in T20. But my focus has been on bowling good lengths. When I get a wicket upfront then it just gives me more confidence [for the rest of the game]."
But what is it that has sparked his turnaround this season?
He has been bowling a lot quicker - his average speed has gone from 81.9kph in the IPL till 2021 to 86.6kph this season - and has also managed to put more revs on the ball. Former New Zealand captain Daniel Vettori believes these things have also helped Kuldeep bring more energy into his action.
"More revs mean your hand position and your release point [are better] and the more energy you bring to the crease," Vettori told ESPNcricinfo's T20 Time:Out. "The great Shane Warne talked about how your energy at the crease shows how much spin you get in the ball - you need a quick arm speed, and then your subtleties and nuance come from your wrist position."
"Looks like Kuldeep has got the energy, a faster arm action, and now he has got the skill to take over because of that base. It's also the release point. It's about bowling fast with more revolutions on it, and you see the seam position."
"It felt like during the last opportunity he tried to buy wickets, and that maybe [was] a product of Narine being a certainty and [Varun] Chakravarthy coming into the team. 'I have got to make the most of this opportunity because If I don't do something, I'm going to be out of the team.'
"Now he seems more settled - he is obviously the first choice for Delhi and he is forcing his case for being back in the Indian team. It's all about what he's done and how he's improved as a bowler."
Former West Indies fast bowler Ian Bishop also believes that Kuldeep bringing in that extra dimension of adding pace has brought him success this season.
"Virat Kohli, the captain [of India] at that time, wanted him [Yuzvendra Chahal] to bowl with more pace as wristspinners in world cricket have done. The Rashid Khans, the Imran Tahirs were bowling quicker through the air.
"Kuldeep has recognised that in order to be successful in this format 'I too have to add a little bit of pace to the ball and be able to spin it'. So whether that's been a deliberate effort [or not], I think that was good planning. And to see him bowl with more pace is actually working."
Chahal and Kuldeep were once a crucial part of India's white-ball plans before falling out of favour due to inconsistent performances. They both have now made strong cases: Chahal is the leading wicket-taker in the tournament, with Kuldeep right behind. But there is no competition between the two, at least according to the latter.
"He is like my elder brother, and he has given me encouragement," Kuldeep said. "He used to talk to me constantly even when I was injured. I sincerely wish that he got the Purple Cap."