Calcutta: Jonny Bairstow insists that his batting in ODIs is still a "work in progress" despite hitting consecutive centuries to help England to a 3-2 ODI series win in New Zealand.

"Obviously, opening the batting is a bit different to batting in the middle-order. So, my job is now to go out, try and score big hundreds and contribute to match-winning scores," he was quoted as saying by a UK-based sports website.

"That's something I'm really trying to set my mark out to do. It's something that is still a work in progress and will hopefully continue to be for a long time. There's more to come...

"It's a case of just giving yourself a little bit of extra time at the top. It's something that you talk about quite a bit and then when you're actually out there and doing it, it can be quite frustrating especially when you look up and you might only be on one or two off 10 balls.

"But nowadays you can try and catch that up a bit later on," Bairstow added.