Birmingham - The Proteas, almost certainly out of the 2019 World Cup, will do a lot of soul searching in the days and weeks to follow. 

Wednesday's four-wicket loss to New Zealand at Edgbaston means that Faf du Plessis and his men have lost four of their six matches at the tournament. There was a washed-out 'no result' against the West Indies, while a win over lowly Afghanistan is all the South Africans have to show for their efforts so far in England.

It is, quite easily, South Africa's worst ever performance at a Cricket World Cup.

The anger from back home is something that Du Plessis anticipates and understands, but supporters of this team will want answers.

Where did it all go wrong?

South Africa never entered the competition as favourites, but they were still heavily fancied to make a semi-final and were certainly not expected to struggle as much as they have done.

Injuries were obviously disruptive, but they do not excuse the performances that have been dished up over the last three weeks.

All the talk pre-tournament from the Proteas had centred around their fast bowling attack. That was to be their major weapon and, according to Du Plessis and coach Ottis Gibson, was their ticket to the World Cup final.

What they didn't expect, though, was their batting being so toothless when it mattered most.

Since their tournament opener against England at The Oval back on May 30, the South African top order has failed to convert encouraging starts into innings of substance.

Quinton de Kock's pair of 68s against England and Afghanistan are still the highest scores by a Proteas batsman at the tournament.

When they have needed a player to stand up and post a game-changing score, the Proteas have had nobody answer the call.

Rassie van der Dussen's 67* (64) on Wednesday was about as good a knock as any South African has played in the tournament, but there was nobody else for South Africa on the day doing anything game-changing.

Hashim Amla (55 off 83), Faf du Plessis (23 off 35), Aiden Markram (38 off 55) and David Miller (36 off 37) all threatened to put the Proteas in a commanding position, but none could.

241/6 after 49 overs was all the Proteas could muster, and in reply New Zealand illustrated the value of having a big-situation player in the form of skipper Kane Williamson who carved 106* (138) to take his side home.

When the dust has settled, that inability of the batsmen to post significant totals will emerge as one of the most glaring reasons for South Africa's early exit in 2019.

"If you look at our batting unit, we've got some future talent and some promising players, but if you put our top six against other top sixes around the world, purely on a numbers point of view, we won't be in the top three when it comes to that," Du Plessis acknowledged in Birmingham after Wednesday's devastating loss.

"It's just pure numbers on the board.

"If you look at opposition, there's been big runs scored by batting lineups.

"We've got a pretty youngish batting lineup if you take Rassie, Aiden, guys like that, even Andile to a degree. He's going really good at his cricket, but he's young in terms of putting innings together.

"So we're not as experienced perhaps as other teams when it comes to that, but, the reason why I say we're not as good as other teams is we're just not producing scores or innings that can win you games."

A look at how the South African batsmen have performed individually at the World Cup paints a clear picture of what Du Plessis is talking about.

Proteas batting averages and highest scores at CWC 2019:

Rassie van der Dussen - 60.00; 67*

Quinton de Kock - 38.20; 68

David Miller - 35.00; 38

Faf du Plessis - 32.00; 62

Hashim Amla - 30.25; 55

Aiden Markram - 24.75; 45

JP Duminy - 18.66; 45

The Proteas must somehow pick themselves for a clash against Pakistan at Lord's on Sunday in what is effectively a dead rubber.

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