'It is the most beautiful format of the game'

India captain Virat Kohli has issued a spirited defence of Test cricket and has admitted he's worried that commercial concerns are eroding the quality of the game.

By almost any measure, Kohli has ascended to become the world's leading batsman across all formats, with his brilliance in the traditional form of the game matched by his dominance of limited-overs cricket.

The 29-year-old is the Indian Premier League's most valuable commodity, while there's a case to be made that he's the greatest one-day international batsman of all time with 35 hundreds from 211 games and a batting average of 58.

But Kohli insists Test cricket remains the game's pinnacle, endorsing the International Cricket Council's plan to launch a Test Championship next year and expressing his desire to keep the format a five-day affair.

"I think that if you really understand the sport, if you really love the sport, you understand Test cricket and you understand how exciting it is," Kohli told Wisden.

"I cannot explain to you the job satisfaction that you get when you do well in Test cricket, because you know how demanding it is. It's the most beautiful format of the game.

"I don't think it's going to go anywhere. I don't even see it getting compressed to four days. It should not be tinkered with.

"I think the Test Championship is going to give a huge push to Test cricket. It makes every series more competitive, and there's going to be ups and downs throughout the Championship, which I really look forward to."

Kohil stressed the importance of cricket boards prioritising domestic first-class cricket in an era where T20 leagues are popping up all over the world.

"If you're not going to give more importance to first-class cricket, then people are going to lose motivation to play the longest format of the game," he said.

"And with the T20 format coming in I think there's far greater responsibility on all the cricket boards across the world to treat first-class cricket really well, because if the facilities and the standard goes up, then the motivation always stays.

"You don't want players to get into that mindset where they're finding the easy way out."

Kohli also ruled out participating in the initial stages of the England and Wales Cricket Board's innovative and controversial 100-ball format.

The ECB's new eight-team tournament is set to begin in 2020 and sees each side facing 15 six-ball overs, culminating in a final 10 deliveries.

Kohli said he did not want to be "a testing sort of cricketer for any new format".

"Obviously for the people involved in the whole process and the set-up it will be really exciting but I cannot think of one more format, to be honest," he continued.

"I am very ... I wouldn't say frustrated but it can get very demanding of you when you have to play so much cricket.

"I feel the commercial aspect is taking over the real quality of the cricket and that hurts me."