England sealed an emphatic innings and 98 run victory over a surprisingly timid South Africa in Durban. The nature of the win has, for many, answered the questions I have raised over the course of this tour about the balance of a four man bowling unit, but in this slightly Jekyll and Hyde blog the problem will be re-examined in light of the events of the last week.

However, to avoid coming across all Bob Willis it is more than a little important that the win itself is at least touched upon, and what a win it was. Andrew Strauss said it was as good a victory away from home as he could recall and who can argue with him. Victories by an innings are rare against the major cricket playing nations, but to defeat the top ranked Test nation by such a margin in their own back yard is something worth heralding.

It was a victory to which everyone can lay claim. Trott and Onions may not have got the runs or taken the wickets they wanted but Trott withstood scrutiny in fading light on the second evening when losing another wicket would have dented any chance of such a sizable total, and Onions new ball bowling provided just the challenging control that the Kookaburra ball needs before the shine quickly disappears.

On another day this win could have belonged to either of them, but instead it was four others who soaked up the humidity down by the sea and returned performances of pure brilliance.

Stuart Broad and Graeme Swann produced one of those memorable sessions of international cricket on the 4th evening which is usually reserved for the Ashes to reduce South Africa to 50 for 6. For Swann, his 9 wicket haul for the match was a fitting end to a stunning renaissance year, almost a decade on from his debut. He is a reminder to all finger spinners that you don't need to dislocate your wrists or have a doosrah in your armoury to be successful, because simple mastery of your art will still confound batsmen at the highest level.

Broad again underlined his potential, taking three Proteas wickets for a single run at one point in his spell. It is easy to forget when he produces spells like this that he is only 23, and although fans may be desperate for him to turn in performances of this calibre every innings he is still learning his craft. That said, the ability is clearly there and the more he concentrates on trying to hit the top of off stump the quicker he will develop into a strike bowler to be feared.

With the bat, the two players under most scrutiny delivered characteristically contrasting innings and got the centuries they deserved. Despite averaging over 40 for the calender year, Alistair Cook has struggled to get beyond starts and there have been a few questions raised over whether he can produce match winning innings at the top of the order. His technique has undergone some tweaking and his innings was a lesson in mental restraint as he stubbornly refused to be drawn into the airy wafts outside off stump which have cost him his wicket over the last 18 months. For much of his 118 he was far from fluent, but his gritty performance and partnership with Paul Collingwood set the perfect platform for Ian Bell.

Bell has always been something of an enigma. As exemplified in the First Test he is does not seem to be a man for the crisis, but he has shown time and again that with a suitable foundation he can get England into a winning position. The tentativeness shown when England were struggling in the First Test was replaced by the sort of easy stroke play which has become his calling card. There can be no doubt that somewhere in there is a truly quality Test batsman, which brings us once more to the question of balance.

The first and arguably most important point was raised by Nasser Hussain. Simply put, this is not an issue of whether or not Bell is good enough to play for England. In truth it never has been, Bell has a good average and has shown again over the course of this last match that he is wonderfully gifted young man with many years of top level cricket left in him. That said, he would not have been in my England team before this century, and despite this wonderful innings he would not make the cut for the first Test of 2010.

Test match cricket has one major difference to One Day Internationals, namely the wicket requirement. In ODI's you can lose nine wickets and defeat a side you lost one, as a result of having more runs. In Test matches you can score infinitely more than the opposition but without 20 wickets it is meaningless and the game will meander towards a draw. England managed to do that in this game but I do not for one second that this four man attack will produce the required results on a regular basis for the following reasons.

Firstly, you cannot expect the opposition to be as bereft of fight as the South African's apparently were. Their tentative batting did not befit the top ranked side in the world, and for three quality batsmen to be dismissed attempting to leave the ball in such short time is unforgivable. Add to that Amla's poor dismissal and you have to accept that 4 top batsmen gifted England their wickets. This was less a case of bowlers defeating batsmen than it was a case of batsmen waving the white flag.

A further point would be that the South African bowling attack may have had five obvious prongs in name, but this was at best a three man attack in combination, with Kallis and Steyn only half fit and Ntini all but anonymous. de Whet must have been sat on the sidelines wondering what on earth he had to do on debut to warrant a place in this distinctly average bowling line up. For South Africa to pick Ntini over him for the next match would be at best sentimental ignorance. As a result, England will have to work a lot harder to give their bowlers such scoreboard pressure.

The inference would be that this was not a case of one unbalanced side being defeated by a balanced one, but rather a case of the least unbalanced side triumphing. England still need to win one of the remaining two Tests to be assured of victory and their best chance of victory does not lie in the hope that Graeme Smith's men will be as bad second time around. As a result, cruel though it is I would replace Bell with a bowler rather than gamble that four will be enough.

A nod to recent history would suggest that England have their best chance of winning with a five man attack. Few would suggest that England are a better bowling unit without Andrew Flintoff, and if the selectors didn't feel four was enough with him it seems odd that they suddenly feel that four is enough after his retirement. As the last man in, Bell would be the first man out, but this does not mean international exile. Think how long Hussey, Katich and Watson had to wait to prove their class. England should be thankful to have six batsmen and wicket keeper with such batting quality, but it doesn't mean that playing them all in the same side will bring victories of this magnitude on a regular basis.