Eoin Morgan "is the single biggest factor" in England's success in white-ball cricket over the last two years, according to the team's assistant coach, Paul Farbrace.

Morgan, the side's captain, could easily have been sacked after leading England through a dismal World Cup campaign at the start of 2015. Not only was the team knocked out at the group stages, but Morgan himself suffered a run of form in which he scored just two runs from four ODI innings at one stage and five ducks in 11 innings at another.

Instead, the team management recognised that he had inherited the position in far-from-ideal circumstances - just a few weeks before the tournament when Alastair Cook was sacked just before Christmas - and retained faith in his leadership.

It is a decision that has paid off. While the England team are only No. 5 in the ICC's ODI rankings, their white-ball cricket has been revolutionised. They were the first team in this tournament to qualify for the semi-finals, they reached the final of the World T20 last year, and they have - among an array of broken records - set the highest ODI total in history: 444 for 3 against Pakistan in Nottingham last August. It is all a far cry from the stuttering mess of the World Cup campaign.

"I think Eoin Morgan is the single biggest factor in England's success in white-ball cricket over the last two years," Farbrace said. "Andrew Strauss took a lot of credit in that he talked about the emphasis being on white-ball cricket. And Trevor Bayliss has come in as a very experienced coach, and been very successful in white-ball cricket.

"But for me, Eoin Morgan is the single biggest factor."

The resurgence started at Edgbaston, the scene of Saturday's Group A showdown with Australia. Coming out of a World Cup campaign in which New Zealand had thrashed England in Wellington with embarrassing ease - there were an eye-watering 226 deliveries of the New Zealand innings remaining when they completed an eight-wicket victory - you might have expected confidence to be low.

But Morgan revived flagging spirits, welcomed in new faces and insisted that - come what may - England should look for the positive option. Despite losing a wicket to the first ball of the match, and another in the eighth over, Morgan attacked from the start and, with Joe Root and Jos Buttler contributing centuries, helped lay the platform for a total of 408.

So, as England return to the ground to take on Australia, it was only natural that Farbrace's mind should look back on the seeds of the recovery.

"We all thought we were doing the right thing at the World Cup," Farbrace said. "And quite clearly we weren't.

"We made some mistakes, we didn't play with much confidence. We were all part of it, and I was fortunate I was one of the ones that continued.

"At the time the thought was that Australia and New Zealand were the first two games, we should get them out of the way. Then win the rest of our games and qualify for the quarter-final and build momentum for the semi-finals.

"But I don't think we ever recovered from those two games. I think the mauling we took from Australia in Melbourne, and then the absolute hammering from the Kiwis, it knocked the confidence of all of us, players and staff. Then it became a very tough few weeks.

"In the build-up to that game here at Edgbaston, where we got 400, Eoin talked to the players about going and playing their own way and backing themselves to play their own way. His words at that stage were 'go and play, go and back yourself to play. We're right behind you and there'll be no one getting stuck into you if you come out having played an ordinary shot'.

"Then he went out and did exactly that in the first game. And then he continued to do so throughout the series. I think players started saying 'It's okay to do it … not only is he saying it, but he's actually living it, doing it'.

George Dobell is a senior correspondent at ESPNcricinfo