England are learning - these are the World Cup issues they need to solve

The most surprising moment of England's thumping win over Sri Lanka at The Oval was not Jofra Archer's direct hit run-out, nor Tom Banton's first international century.

It came in an answer that coach Brendon McCullum gave afterwards.

"We are also trying to include a number of warm-up games as well," McCullum told BBC Test Match Special of his winter plans.

That is McCullum, the coach whose side had only one in-house warm-up before last winter's Ashes, talking about arranging 50-over practice matches - something England have not had on a tour outside World Cups for six years in the longest white-ball format.

"A lot of these guys just haven't played a lot of white-ball cricket," McCullum said.

It was an eyebrow-raising, yet encouraging, answer which hints at a change in McCullum, who has also had a beefed-up backroom staff this summer and spoke on more than one occasion about fitness in the Oval aftermath.

And a team that lost six of seven ODI series between their final match of a dismal 2023 World Cup and the end of last year - exiting the Champions Trophy without winning a game in between - have won all three of their 50-over series this year.

With the next World Cup a year away, England may not be the best 50-over side in the world, but they are no longer the format's biggest underachievers.

"I think they might be in with a shout, with a bit of luck on their side," said former England spinner Phil Tufnell.

There is hope again, albeit with some issues to solve…

England win series as Banton delivers on potential

Banton blasts England to series win

Alternatives to Duckett emerge

In the most bizarre of cricketing summers, Ben Duckett has had a bizarre summer of his own.

The only Englishman to compile a Test ton, and the scorer of 141 against India in a one-day international at Lord's, ends with nine scores below 20 from his other 15 innings.

He was talked about as the world's best all-format batter after his 149 against India last summer but has averaged 27.15 since then across formats.

It is right that England are reticent to drop a batter who has hit such highs, especially as a senior player and one with significant List A experience - a total of 111 matches - behind him in a squad still lacking in 50-over matches.

Duckett and Jacob Bethell also shared an opening stand of 192 in the series decider against India at Lord's.

But, unlike the Test side where Emilio Gay's place as Duckett's partner is not fully secure, never mind a replacement waiting in the wings, Tom Banton and Bethell have shown there could be another world without the diminutive left-hander.

Bethell, who scored 91 in the third ODI against India before missing the Sri Lanka series with a knee injury, is talked of as a senior player in the group, despite still being just 22, while Banton's first England century on Sunday was superb.

The way Banton hits the ball at the top of the bounce looks suited to the bouncy pitches of South Africa, where the majority of the World Cup will be played.

Duckett, in contrast, averages 23.4 on surfaces deemed as 'high bouncing' since the start of 2023. This winter's Test series in South Africa may shed some more light.

A bad week for Rehan Ahmed

This was supposed to be the series Rehan Ahmed got his long-awaited chance as England's leg-spinner with Adil Rashid injured. That the 22-year-old was dropped for the series decider is of obvious concern.

Ahmed bowled better than figures of 1-46 suggested in the first ODI, but was flattered by a return of 2-48 from eight overs in the second.

In his place at The Oval, Liam Dawson - 14 years his senior - took 3-26.

Dawson was helped by the combination of turn and bounce on offer from the surface, something Ahmed was not afforded earlier in the series.

But he also landed 39% of deliveries on a spinner's 'good' length, compared to the 22% from Ahmed in the previous two games.

Ahmed is clearly talented but has not progressed as an international cricketer. A sloppy run-out in Durham and a five-ball duck in the Headingley chase did not help his cause.

It leaves Rashid, who will be 39 at the World Cup, as important as ever.

England's depth is building

While the alarming statistics that England have won only one of their past nine ODIs in which neither captain Harry Brook nor number three Joe Root made fifty remains, Sunday's win was significant given the key contributions from other names.

Banton laid the platform of their 355-7 and Jordan Cox's 52-ball 76 pushed the game beyond Sri Lanka.