The one (final) upgrade that can take South Africa's bowling from good to exceptional

Before you continue, this is a disclaimer: what you're about to read is not criticism, but observation; the kind of thing someone tells a gifted student who can get just a little bit better and become exceptional. And that's one of the qualities the team that ultimately wins the World Cup will have.

With that in mind and the knowledge that South Africa have won four out of their five matches and their batting line-up is shaping up as among the best in the tournament, let's touch on an area of concern for them: death-bowling.

South Africa have conceded a significantly higher amount of runs against lower order batters than any other team: 588 runs for wickets seven to 10 in their five group matches so far. It's worth reiterating that these runs came with games all but won.

Sri Lanka were 233 for 7 chasing 429 when their last three wickets put on 93, England were 84 for 7 chasing 400 and reached 170 and Bangladesh were 81 for 6 in the 22nd over, chasing 383, and ended up batting until the 47th over and made 233.

As a result, it is entirely plausible and even understandable that by that stage South Africa's bowlers had lost some interest and allowed things to drift until the inevitable conclusion was reached. Except that in the Bangladesh game, that's not what South Africa were doing at all.

According to stand-in captain Aiden Markram, his bowlers opted to "go death," to Mahmudullah who "got in and batted exceptionally well" he said at the post-match presentation afterwards. He indicated they were using that game to experiment with their tactics, "not that you are practicing, because you are never practicing in a match but we thought we would go death to him and there were some good signs. But there were one or two that we missed that went but that is death bowling ultimately. If you get it wrong, it tends to disappear."

So, what exactly do South Africa consider "going death" and who does it? From what we can see in the first five games, Kagiso Rabada and Gerald Coetzee are their primary death bowlers and their intention is to send down a mixture of yorkers and slower balls.

Coetzee tried both against Bangladesh, without much success. One came out as a full toss which Mahmudullah pulled to mid-wicket and would have probably been out if it was not a waist-high no-ball. The second one was read out of the hand and driven over long-off for six and the third was simply too full. Rabada also struggled to execute the yorker and ended up delivering juicy full tosses.

In total, according to ESPNcricinfo's ball-by-ball data, South Africa have sent down 16 full tosses, which is only half as many as Sri Lanka, who have the most in the tournament, but still puts them in the top five. New Zealand, as a measure of contrast, have bowled only three. On the other side of that fine margin, South Africa have bowled 13 yorkers, which is between two and three a game, while India, widely regarded as the best attack at the tournament, have nailed the delivery 33 times.

The other option for many attacks at the death has been to take pace off the ball but the data shows that South Africa have only bowled only 20 slower balls in 43 overs. Even accounting for errors in the capturing system, simply watching them reveals that it isn't something they go to instinctively. And the coach who stressed the importance of variation, Charl Langeveldt, is no longer part of the support staff, though they do have Eric Simons in the bowling consultant role and he would know better than most what the strategy should be.

It also does not help that South Africa's death-bowling specialist Sisanda Magala was ruled out of the tournament with a knee niggle before the squad traveled to India. Magala has since played two games for his provincial side, the Lions, albeit none in more than three weeks, which vindicates South Africa's concerns about his conditioning. What they did not want to risk was bringing him to India and then losing him for some matches, as has clearly been the case for the Lions. But that does not mean they can't find someone else who can do a similar job.

Lungi Ngidi, who missed the Bangladesh game, also with a knee concern, is expected to be back soon and, with an array of slower balls to offer, could be an option. So far, he has only bowled once in the last 10 overs which may be a consequence of using him to open the bowling and the success that South Africa are having early on.

No team has been fewer than eight wickets down against South Africa going into the 41st over, which means they haven't batted a full 50 overs against them. All that said, putting the spotlight on death-bowling can seem hypercritical of a team that is in control for most of the other passages of play so far but, with more challenging opposition on the way and the knockouts in their peripheral version, it's an area of the game South Africa will want to get right.