STEVEN FINN is relieved and delighted that England are delivering at last on their best intentions in one-day international cricket.

The fast-bowling linchpin of the hosts' impressive Royal London Series campaign regrets that World Cup captain Eoin Morgan was collectively let down in a series of hapless performances which spelled an embarrassingly early exit last winter.

England were talking a good game even back then about their determination to play with adventure - but somehow, it simply never happened.

As they prepare for a decider against New Zealand this weekend, though, Finn can speak from a position of comparative strength about England's latest 50-over escapades.

An all-time series record number of runs is in the offing at Chester-le-Street, where an astounding aggregate of more than 3,000 is almost assured between two teams level at 2-2 after another feast of boundaries at Trent Bridge.

There, Finn's figures of one for 51 in 10 overs deserved an asterisk for context as he and Mark Wood recorded the only frontline analyses under seven an over on either side.

As at every stop so far in a manic series, the batsmen were largely unstoppable, and even a modicum of success with the ball was notable.

England's transformation in four months from World Cup also-rans to stern opposition for the finalists is remarkable - and something which understandably gives Finn great encouragement.

"We've talked a lot about playing with a carefree attitude and with freedom - we talked a lot about it in the winter but never did it," he said.

"We talked about what we wanted to do in the World Cup. We sat in front of you guys and said we wanted to play with freedom, smiles on our faces.

"We didn't do it. I can't put my finger on why.

"So it's great that four games in a row now, win or lose, we've played with that attitude."

Within 12 hours of England's highest ever run chase, it was confirmed Finn is part of current plans too in both other formats.

His was one of just five names to appear in the squad to take on the Kiwis again in Tuesday's one-off Twenty20 at Old Trafford and also travel to Spain the following weekend on a pre-Ashes training camp.

Morgan is not in the second of those lists, of course.

But Finn is gratified by his captain's dramatic return to form - with four successive 50s, the last turned into a man-of-the-match 113 as he and fellow centurion Joe Root made a mockery of a previously out-of-range target of 350.

"The World Cup hurt everyone, and it would have hurt him being the captain and a proud man," said Finn.

"Talking a lot in front of ... people and us, as players, not backing him up would have hurt him massively.

"We know he is such a good guy and everyone wants to be behind him and respect him as a captain.

"He is in the form of his life - I've never seen him hit a cricket ball like he is in the last few weeks.

"It's great to be playing underneath him, brilliant."

As for the bowler's lot in white-ball cricket, Finn has simply had to update all requirements and expectations.

"It's exciting to be a part of - but yes, when you get whacked around the park, you don't quite enjoy it as much.

"It's like playing a long Twenty20.

"You almost have to accept you're going to be hit for boundaries.

"It's just trying to make sure they are playing good shots to get their boundaries, and they are not hitting bad balls."

Previous rules of what is an attainable run rate seem to be obsolete.

Finn said: "It has changed big time since the World Cup.

"(Brendon) McCullum hit me over wide long-off for six - and I thought: 'That was probably hitting the top of off stump.'

"So you have to walk back and think: 'Fair play, that was a good shot.'

"It's that sort of attitude that bowlers are having to take into games.

"It is about having a clear plan and saying: 'If you hit me while I'm bowling to this plan, then you've got the better of me - and (you) are too good for me today.'

"It is very much like Twenty20 cricket ... a 50 over-long Twenty20."

The second half of England's summer, fast approaching, will be a very different matter - and after his much-chronicled growing pains as an international bowler over the past two years, Finn is back in the mix.

He and uncapped Derbyshire left-armer Mark Footitt were the most eye-catching among the 14 names announced for the four-day Iberian training camp when England's hopefuls will get to know new coach Trevor Bayliss.

"I'd love to play in the Ashes," said Finn.

"It is the pinnacle of what you can achieve as an England cricketer ... but at the moment I'm opening the bowling in the one-day team and really enjoying that challenge."