England 287 for 6 (Bell 82, Morgan 49, Buttler 47*, McClenaghan 3-54) beat New Zealand 253 (Taylor 71, Tredwell 3-51)

They may have won, but England left Trent Bridge with many questions still unanswered ahead of their Champions Trophy campaign. While a victory over New Zealand - on the face of it a comfortable victory - was welcome, it did little to answer some of the unsettling queries this series has thrown up.

Most pertinently, they must ask themselves whether the outrageous contribution of Jos Buttler, in particular, and Eoin Morgan, in the dying overs of England's innings, vindicated the sedate progress of England's top-order in building the foundations of the late assault. Or whether the pair's remarkable counter-attack simply masked the flaws in another worryingly passive batting performance. There is, no doubt, some truth in the former, but there may well be rather more in the latter.

There are other questions, too. With James Anderson and Graeme Swann rested from this game but all but certain to play in the Champions Trophy, England provided opportunities to the likes of James Tredwell and Ravi Bopara. James Tredwell, in particular, was impressive which raises the conundrum of whether England might be best fielding two specialist spinners and which seamer would make way.

And while Ravi Bopara was far from fluent with the bat, he did help eke out 57 runs for the fifth wicket and bowl the most economical spell of all the seamers. Once again, on the eve of a major event, England's plans, their settled team and their role definition, are not quite so clear as they appeared a week ago.

Certainly England would be wrong to congratulate themselves too heartily on a dead-rubber victory over a New Zealand side who started the series ranked No. 8. For most of their innings, England batted with little intent or flourish and the New Zealand bowlers controlled them as a collie might some sheep. New Zealand still won the series 2-1.

Indeed, had it not been for the partnership between Buttler and Morgan - a ridiculous 62 runs from 22 legitimate deliveries - New Zealand would surely be celebrating only their second ODI whitewash (following the 3-0 victory in New Zealand in 1982-83) and England would be licking their wounds on their first home whitewash since Sri Lanka beat them 5-0 in 2006.

Buttler remains a raw talent. Later he missed a relatively straightforward stumping off the bowling of Joe Root - Kane Williamson, on 14, was the fortunate batsman - that might, another day, have proved crucial. There will be days, too, when his high-risk approach with the bat does not pay off.

But, when it does come off, it will be spectacular. Here, with an unbeaten 47 from just 16 balls, he delivered a most un-English display of hitting that made a nonsense of the prodding and poking from his colleagues that had preceded it. He turned this match on its head. Not just that, but he did it in a handful of overs. Very few players can do that. Even fewer of them are qualified to play for England.

While his team-mates, the admirable Morgan apart, struggled with their timing throughout, Buttler batted with the power and invention that underlined the talent that has seen him fast-tracked into this England side.

Not every stroke came off the middle of the bat - Buttler enjoyed a couple of fortuitous edges that ran to the boundary - but his boldness was rewarded and helped England plunder 76 from the final four overs. It was testament to a special talent, certainly, but also the nerve and hardwork of a young man who may well drag this England team into the modern age of limited-overs batting.

Buttler signalled the attack by thrashing a length delivery - the third he had received from Kyle Mills - over midwicket for six before producing his trademark ramp shot to the next ball - a perfectly respectable delivery outside off stump - that brought four to fine leg. The next delivery was clipped through midwicket for another four before Buttler shaped to ramp again but, seeing the ball well outside off stump, instead lifted it over short third man for another four. It meant Mills' over had cost 22 runs.

With two more sixes in the final over off Tim Southee, Buttler faced the final ball of the innings requiring five runs to set a new world record for the fastest ODI half-century. He could manage only two, however, so Sanath Jayasuriya's 17-ball record, set in Singapore against Pakistan in 1996, remains.

Morgan, with 49 from 40 balls, also impressed. Having taken 16 balls to score his first eight runs, he struck three sixes - two over long-on and one over long-off - to add the impetus that England so dearly required.

The ferocity of the counter attack - and its unconventional nature - appeared to unsettle New Zealand. Mitchell McClenaghan, who had been immaculate in claiming 3 for 23 from his first eight overs, conceded 20 from his final over, which included a succession of wides and no-balls.

Until the sixth-wicket paid came together, the England innings had struggled to move out of second gear. Ian Bell laid something of a platform with an innings of 82 off 96 balls, but failed to fully capitalise and none of his top-order colleagues could stay with him or accelerate as required.

McClenaghan, a scourge of England throughout the series, bustled in to trap Alastair Cook and Jonathan Trott with straight deliveries, while his third spell ended Bell's innings when the batsman drove to mid off. Root, dropped on 10, could edge just one boundary in his 50-ball stay and Bopara, thrashing around like a drowning man, could not find it at all in his 38-ball stay as England made Williamson, the part-time offspinner, look like Muralitharan.

New Zealand started their reply well. Martin Guptill, with unbeaten centuries in his previous two games, looked in fluent form and they raced to 70 for 1 before the end of the 10th over. While Stuart Broad, bowling with impressive pace, had Luke Ronchi caught at mid-on after he was late on an attempted pull, the seamers were, at that stage, proving expensive.

The introduction of Tredwell made an immediate impact. He might have been unable to take a first-class wicket so far this season, but he produced a perfect off-break in his first over here to bowl Guptill, pushing forward, through the gate.

Tredwell took some punishment later at the hands of the excellent Ross Taylor - who recorded a half-century in every game of this series - but eventually had his man caught on the midwicket fence (Steven Finn, realising he was going to topple over the boundary, throwing the ball to Tim Bresnan in the nick of time) and also had Brendon McCullum caught behind as he tried cut on too full for the stroke.

Root also struck in his first over, defeating Williamson's pull stroke with an off break, Colin Munro fell to his first ball, following one angled across him and, by the time Nathan McCullum was well caught by Broad running back at mid-off, the game was as good as won.

New Zealand could leave Trent Bridge secure in the knowledge that they know their side and their method, but this was an evening that belonged to Buttler.

George Dobell is a senior correspondent at ESPNcricinfo