Former England skipper Alastair Cook recently weighed in on the debate surrounding the "Big Four" in Test cricket - Virat Kohli, Steve Smith, Joe Root and Kane Williamson.

Joe RootAccording to the former England skipper, Joe Root is the best among the "fab four" in the longest format of the game. Root currently stands out as the most in-form player, edging slightly ahead of his counterparts, thanks to his consistent performances over the past year.

Cook also acknowledged New Zealand's Kane Williamson as the closest competitor to Root in terms of form over the last year. Speaking during a round-table interview hosted by the ICC, Cook praised Root's exceptional run with the bat.

Currently, Root is the fifth leading run-getter in Test cricket with 12,716 runs and is 3,026 runs shy of going past Sachin's Test tally. 

"I think at this precise moment in time, I find it hard to see anyone playing as well as Joe Root," Cook noted. "Over the last year or so of the so-called 'Big Four', I think Williamson and him are probably in the best form at the moment."

While players like Kohli and Smith have had their share of ups and downs in the past year, Root and Williamson have maintained a high level of consistency, a trait which has set them apart.

"They're all wonderful, wonderful players, all very different, actually, in their methods and ways of playing. But one thing which, kind of unites them is that hunger and desire to keep improving and keep churning out the runs," he said.