New Delhi, Nov. 30 -- Vishnu Vardhan, a four-time national singles champion, has been part of the professional tennis circuit for over two decades. He has represented India at the highest level, the Olympics, the Davis Cup, and famously won bronze in men's doubles and silver in mixed doubles alongside Sania Mirza at the 2010 Guangzhou Asian Games.

But today, the racquet sport catching the eye of his seven-year-old son isn't tennis. It's the one Vishnu himself has been actively promoting and playing, a sport that has turned into a nationwide fever over the past few years: Pickleball.

"Just before leaving for school, he'll say, 'Come down, let's play pickleball,' and we just go downstairs and play," Vishnu told Hindustan Times. The point ...