Both the Australian and English captains have questioned the state of the pitch in the fourth Ashes cricket test in Melbourne.

Australia captain Steve Smith said it ended up being quite boring.

"I think it needs to have at least something in it, you know a bit more pace or able to break up so it spins or just something, you know it was just completely flat for five days."

Smith's defiant 23rd test century has helped the hosts retain a 3-nil lead in the Ashes heading into the final test in Sydney.

England skipper Joe Root said it's hard to get much success with the ball on such a flat wicket.

"We did everything we could to do so, it's obviously a very flat wicket not offering the bowlers much at all. No pace in there, no spin, I think if we played for another four days it would be exactly the same."

Little assistance in the form of grass or cracks were offered for the bowlers in the match, with over a thousand runs scored for the loss of just 24 wickets.

The final test gets underway on Thursday.