England show the promise and pitfalls of playing a side full of young players

If you have a young side, there are going to be times when they make errors.

And, for a moment, as Zak Crawley clipped to backward square and Dom Sibley deflected to leg gully, there was a sense of frustration. They had scored 44 and 36 respectively. They had done the hard work. England needed them to go on and register the huge scores that define matches.

But then comes the pause for reflection. And the realisation that this opening pair has a combined age of 45. That they have played eight Tests between them and yet still found a way to compile England's longest first-innings opening partnership when batting first since 2009. It's probably not fair to expect a huge amount more from them at this stage.

Crawley was in two minds by the close of play. He felt, he said, that he had "played well" and he was encouraged by the time he had batted. By doing so, he felt he had proved to himself that he had what it takes to make Test centuries.

"To score a hundred, you need to be able to face 180-plus balls," he reasoned. "So to face 130-140 [he actually faced 137] has given me confidence."

But he acknowledged that "once you get to 40, you need to go on and get a big one" and he was conflicted by his dismissal. He could not recall the last time - if ever - he had faced a 6-3 leg-side field and he felt, he said "unlucky" to middle a leg-side half-volley and see it brilliantly caught. At the same time, he accepted South Africa were bowling for the dismissal, so he had effectively fallen into their trap.

"I had a similar ball a couple of overs earlier," he said. "And I hit it over the fielder. I think the ball that got me out would have been hard to keep down - it was the wrong length for that - so I probably should have gone over the fielder in hindsight.

"I feel it was quite unlucky but then again they planned it, so I'm not sure if I'm unlucky."

In short, Crawley, 21 years old and with a first-class average of just 30.28, is learning on the job. And as he - and the other four members of the side aged 24 or under - does so, there will be moments when their inexperience shows.

Sibley could have shared similar sentiments. While his selection is rather more on merit and rather less on potential by comparison to Crawley, he too is being tested in ways he has probably never encountered. Having seen off Vernon Philander with the new ball and Kagiso Rabada a little later, he had performed a key function in the role of an opening batsman. So to perish to the sort of ball he would usually consider food and drink - a short ball on his hips he steered to the cleverly positioned leg gully - was disappointing. But if it was out-thought by some smart South African cricket, it is also worth acknowledging that he forced them into such tactics.

So this was a day that showed the promise and the pitfalls of playing a side full of young players. A day when it was important for management, media and supporters to remember this is a transitional team (had Jofra Archer been fit, England may well have fielded a side including six men aged under 25 for just the second time in their history) at the start of their journey. As long as they learn, as long as they improve, little more can be asked.

In the end, it was a day that finished pretty much even. England will be frustrated that each of their top four made 25 but none went on beyond 44; South Africa may feel the stand between Ben Stokes and Ollie Pope is building ominously. The 76 they have so far added for England's fifth wicket can only be viewed as a foundation but they both look in fine touch. There may be a batsman in England who times the ball as well as Pope - James Vince, perhaps, or Moeen Ali at his best - but it's hard to think of one who times it better. It really does feel as if he is on the cusp of a fine career.

None of England's young batsmen have a ceiling as high as Pope. It's not just the eye-catching strokes he can play - he played an outrageous upper cut off Dane Paterson here, with both feet off the ground, that demonstrated the huge amount of time he has on the ball and the wide range of strokes available to him - but the calm way he takes control of the situation and builds an innings.

When he came to the crease, England had just lost Joe Root in dramatic fashion - his off stump pegged back by Rabada - and were, at 148 for 4, in danger of seeing the advantage of batting first squandered. But you would not have known it from the way Pope took charge. After scoring just one from his first 15 deliveries, he gradually settled to the point where, not long before the close, he took Anrich Nortje for three successive boundaries.

Some may express concern at Root's dismissal. And it is true that his form, over a long period, is not as prolific as his side requires. But he deserves some slack with this one. The ball kept lower than a previous delivery from the same bowler which pitched in the same spot. It didn't feel like it at the time, but it was a dismissal that may well spell worse news for South Africa - who are batting last - than England.

"If we can get in the late 300s that's a very good score on this pitch," Crawley said. "It's only going to get worse from here and it will continue to spin quite a bit. Hopefully a few will go underground like Joe's did and we are bowling last on it."

Much, then, may fall on the shoulders of young Dom Bess. And for all the control he offered in Cape Town, it does have to be acknowledge that England's 22-year-old spinner claimed only two wickets in the match. This will be a new challenge for him.

But that's what you get with young players. And while there is no certainty that all of them will make the grade, there is even more certainty that they won't if they are denied the opportunity or time to grow into the role. This is a new, young England. We are going to have to give them time to learn. On the first day here, they at least proved they offer the potential to go far.