More than a hundred

One of the features of the two leading one-day teams in the world - England and India - is the increasing frequency of bigger hundreds. Just witness what Virat Kohli and Rohit Sharma have been doing against West Indies recently, or what England have done home and away in the last few years. Top-order batsmen are now more regularly going well beyond 'small' hundreds and extending upwards of 130. Australia are struggling to match them: since their slump took hold, in early 2017 away to New Zealand, two individual centuries have gone above 130 - Marcus Stoinis' 146 in Auckland and Shaun Marsh's 131 in Cardiff. India have ten such scores, England six. Captain Aaron Finch has been in fine form of late with three centuries this year, all against England, but they have ended on 107, 106 and 100 with at least 10 overs of the innings remaining. It may seem at the lesser end of Australia's problems, but they need to start being converted into the mega hundreds which are a more regular feature in the ODI game.

In a spin

What do Australia want from their one-day spin bowler? It's a question they need to answer this season. Ashton Agar has been given a run in the team of late, playing the five matches in England where he emerged with some decent performances amid Australia's rubble. He provides an all-round package, with his batting seeing him as high as No. 5 on one occasion. Nathan Lyon played the last two ODIs against England but has been left out for the series against South Africa having notched just 15 matches in the six years since his debut. It's often been one match here, a couple of matches there for Lyon and Australia don't appear any nearer to knowing if they really want him in the one-day side. Legspinner Adam Zampa is back in the mix having had a stop-start career, while it could yet be that, with the World Cup being in relatively early-season English conditions, that a combination of the part-timers may yet be the route.

Middle-order muddle

The absence of David Warner and Steven Smith has left significant holes to fill at the top of the order, but there are also issues in the middle. In England, various combinations were tried without much success. Australia are once again crossing their fingers that Chris Lynn can finally get a run in the side following a string of injuries, while there is the ongoing challenge of getting the best out of Glenn Maxwell after a number of mixed messages from selectors to the player. The unsurprising decision to move on from Tim Paine allows Alex Carey to naturally settle into the side.

Getting the balance right

The numbers show that Australia's strike rates and six-hitting capability are not top of their list of problems (in fact, their average opening 10-over Powerplay return this year of 51.25 is their fourth best) but combing those with keeping wickets intact during an innings has been central to their recent woeful run of form. This year, in the 10 ODIs against England, their average score after 40 overs has been 213 for 6, meaning a final 10-over push is being left to the lower order - see point one about making big hundreds - which leaves little chance of scoring 100 runs. Everyone is now looking to England and India for how it's done in the top four; you can't magic up the likes of Jason Roy, Jonny Bairstow, Rohit and Kohli but Australia's issues are showing up the massive challenge of filling Warner's one-day shoes.

Which quicks?

This is an area Australia are pretty well placed. The Big Three are back together: Mitchell Starc, Pat Cummins and Josh Hazlewood are all in the squad to face South Africa. One of the questions is how much one-day cricket they play in the lead-up to the World Cup. Australia have been able to explore their pace depth in recent times given the absence of the trio in England earlier this year, although all five pacemen used on that trip have been left out of the South Africa series. Billy Stanlake had a lean JLT Cup but his pace could keep him in the frame, while Jhye Richardson has shown promise. Nathan Coulter-Nile has been recalled for this series and his splice-jarring length and extra batting ability will put him in the World Cup mix. Left-armer Jason Behrendorff gave a reminder of his skills for the Prime Minister's XI, although he may be likelier for T20s.