Calcutta: Alastair Cook described Joe Root as a "genius" and the best English batsman he has played with after both of them put on 248 for the third wicket on Day I of the ongoing Day/Night Test at Edgbaston against the West Indies.

"It's fairly frustrating when you have around 30 run head-start and he beats you to a hundred so quickly. It's incredible how Joe manages to score like he does.

"If he's not the best English player I've played with, he's right up there... I think he is... His game is phenomenal and he's just churning out runs.

"He's a genius and an unbelievable player to watch from the other end. How he moves, his rhythm... It's a lesson to us all," the former captain was quoted as saying by a cricket-specific website.

Cook remained unbeaten on 153 at stumps on Day I - his first century since the one he scored in Rajkot last year.

Talking about the knock, the left-hander said: "I don't know why hundreds are such a big thing. I was really pleased with a couple of those 50s in a tough series against South Africa, where it did quite a lot.

"As a batsman, you are judged on hundreds. It was nice when it was tilted in the batsmen's favour, that I managed to cash in."

But it's the 88 he scored in difficult conditions against South Africa at The Oval that seems to please Cook more than the century he got on Thursday. "That 88 was as good a knock as I think I can play in those conditions," he said.

"It was a tough knock with the ball nipping around against four quality seamers. That was very pleasing. In this Test, the sun was out, a flat pitch and it's nice to contribute with a score for England."