Birmingham - South African supporters are experienced when it comes to dealing with Cricket World Cup heartache, but even they will be left scratching their heads after the failures of 2019. 

Wednesday's four-wicket loss to New Zealand at Edgbaston has ensured that the Proteas are the first of cricket's powerhouse nations to effectively be eliminated from this year's tournament. 

With three pool games remaining, this is comfortably South Africa's worst ever showing at a World Cup.

They didn't even fire a shot.

Given the country's dramatic history at the global showpiece and the desperate, seemingly eternal mission to be crowned world champions, this is a catastrophe. 

The Proteas must always be a side near the top of the pile in world cricket, and if they cannot perform like one when it matters most, then questions need to be asked. 

In the days and weeks that follow, Cricket South Africa (CSA) and Proteas management will need to do some explaining. 

Hindsight obviously makes it easier to poke holes in what would become a dismal campaign, but South Africa should never have gone into a World Cup with players who were not 100% fit. 

Dale Steyn sat on the sidelines for four fixtures in England before he was eventually sent home and replaced. 

It was a massive blow to the Proteas, who had nestled all their eggs in one basket, pinning their hopes on a pace attack of Steyn, Kagiso Rabada and Lungi Ngidi. 

That was 'Plan A', but as the tournament progressed, it quickly became clear that there wasn't much of a 'Plan B'. 

The attitude of the leadership and the players also needs to be questioned. 

South Africa's struggles with the mental demands of a World Cup are well documented, and this time around the Proteas came in with a relaxed approach. 

Before a ball was bowled in England, skipper Faf du Plessis went as far as saying that failure to win the tournament would not be the end of the world. 

Given the perceived over-emphasis that South Africans have placed on this tournament historically, Du Plessis' intention was clearly to take the pressure off his players. 

It may have backfired, though, because the body language in the first two matches against England and, particularly, Bangladesh was not good enough.

The Proteas admitted as much, and complacency against a well-drilled Bangladesh outfit at The Oval would result in a killer blow to the South African charge. 

Pretending that there is no pressure at a World Cup is clearly not the answer, because there is and there always will be.

Coach Ottis Gibson cuts a relaxed figure almost all of the time, but his formula has not got the best out of his players. 

He expressed shock at a lack of yorkers against Bangladesh while, after Wednesday's loss to New Zealand, he questioned the slow batting and an inability to take the game forward.

If a head coach cannot get his team to implement philosophies and gameplans, then that needs to be addressed. 

Gibson's contract with CSA runs until the end of September, and at this stage it is hard to see him staying on.

If he does leave, CSA must identify a replacement with a long-term vision in mind. 

There is nobody locally, though, who emerges as an obvious replacement to Gibson.

When Gibson joined as Proteas coach in 2017, he had two years to prepare for the World Cup. 

This time around, CSA must implement a four-year plan that starts from immediately after the 2019 tournament ends. That is what England did after their group stage exit in 2015, and they are reaping the rewards right now.

We always hear about depth in South African cricket talent, and now is the time to prove that it exists. 

Picking players on sentiment can no longer be an option, and if a player is not in form or unable to reach the heights he once did, then he cannot be entrusted with going to a World Cup.

There are the likes of Aiden Markram, Kagiso Rabada, Lungi Ngidi and Andile Phehlukwayo, but are there enough other high-quality youngsters that South Africa can build a squad around?  

If so, who are they? 

Imran Tahir and JP Duminy will retire from ODI cricket at the end of the World Cup, but there can surely be no long-term value in persisting with the likes of Steyn and Amla in the format. 

There needs to be a clean slate. 

Perhaps the toughest call will be on Du Plessis. 

The skipper will be 35 by the end of the tournament and there is surely no way he will be around until 2023. 

CSA will have to think long and hard about his immediate future in the ODI set-up. 

Du Plessis is a man broken by another World Cup campaign that has left South Africans all out of answers.

The problem in replacing him, though, comes back to issues of depth. 

Who is next in line? Markram has barely done enough to warrant selection in the ODI side, so can he realistically be given the captaincy now?

It is another question the CSA leadership must consider. 

Before any of that, though, the Proteas must somehow pick themselves up for three matches that don't matter against Pakistan, Sri Lanka and Australia. 

A World Cup game against the Aussies with absolutely nothing riding on it.

It just doesn't feel right ...

@LloydBurnard is in England covering the 2019 Cricket World Cup for Sport24 ...