The Six Nations enters its final round this weekend and if the climax is as captivating as the previous four rounds, it will paint a colourful, vivid portrait of the state of rugby in Europe.

The Six Nations Under-20 tournament, that is. Wales are chasing the grand slam, needing to beat England at Colwyn Bay on Friday night UK time. They have played with a flourish and the tournament has been a welcome contrast to the senior event, emphasis placed on attack rather than defence.

And so to The Six Nations proper, which started with a flurry of tries, 16 in the first round; there have been 15 in the three since then, and of the four fashioned last weekend, three came from short-range forward rumbles and the fourth was from a kick and catch.

England are in Cardiff on Saturday on the trail of the grand slam. Wales, unlike Wembley in 1999, cannot be content with wrecking the party of the rivals they enjoy beating more than any other. Their title is at stake and they will retain it for the first time since 1979 if they win by eight points or more, seven if England do not score more than one try than them.

Any joy and elation Wales feel at winning would be strongly diluted by the sight of England going up to receive the trophy and showing it off to what remained of the crowd at the Millennium Stadium. They have as much to gain and to lose as their opponents.

If it promises to be a tense, absorbing tussle, on the lines of Twickenham last year when Wales won by seven points thanks to a late try, risk is unlikely to be on the menu. England have scored one try in their last three matches, and that should have been disallowed for an accidental off-side, and if Wales have been more prolific with four, rarely has the ball gone through the hands of their three-quarter who in Rome and Edinburgh averaged six touches of the ball each.

It says a lot that the two most important players in each back division, factoring out the goal-kickers Leigh Halfpenny and Owen Farrell, are the inside-centres, Jamie Roberts for Wales and England’s Brad Barritt: they are both the defence captains of their respective sides and the philosophy of both managements is that defence wins matches.

The aim of both will be to play for territory, taking no liberties in their own half, and both have tended to use the scrum as a means of getting downfield, not by moving the ball but winning a penalty or free-kick and using it to gain an attacking line-out or hoist a high kick.

Both Wales and England have footballing alternatives at 12 in James Hook and Billy Twelvetrees. Hook has gone from being a player the Wales coach Warren Gatland, who is on a Lions sabbatical this championship, described as someone who had to be in the team, whether at 10, 12, 13 or full-back, to an extra: he has been on the bench all tournament but has only twice come on for a combined total of 18 minutes.

Wakes have the most threatening back three in the Six Nations but, without a passer like Hook or Gavin Henson, back playing again regularly for London Welsh, Halfpenny has not been brought into the line and the favoured ploy is for one of the big wings, George North or Alex Cuthbert, to burst into the midfield.

Wales have endured some poor conditions, especially in Italy, but their gameplan has been set for a few years, one based on physicality, power and defence. The caretaker attack coach Mark Jones admitted after the second weekend that passing was not the forte of the centre Jonathan Davies: he has not been made available to the media since.

Twelvetrees made his debut against Scotland on the first day of the tournament in place of the injured Manu Tuilagi. It was England’s first match their victory over New Zealand at the beginning of December and what was notable about their performance was their use of multi-phase possession to create tries.

They scored four that day, some coming from 11 and 12 phases, countering a convention in Europe that once play has gone beyond three phases, the prospects of scoring a try are remote. Twelvetrees helped provide England with width, especially moving from right to left, and as someone who had played at outside-half he, like the full-back Alex Goode, was an alternative first receiver to Farrell.

Scotland were stretched every which way. Twelvetrees retained his place against Ireland in Dublin with Tuilagi only making the bench, but he had little to do on a filthy day and was taken off after 47 minutes. Since then, he has only been used for the final 13 minutes against Italy.

A midfield containing Twelvetrees would have challenged a defence that has not conceded a try for 22 minutes short of five hours. As it is, both defences will deal with straight-line runners in what will be a battle for penalties at the scrum and a fierce scrap at the breakdown.

Wales have recovered well after a run of eight successive defeats, but their style of play is suited to the Six Nations and explains why it is more than four years since they defeated one of the major southern hemisphere nations. If they win the match but lose the title, it would show that all-out defence is not enough.

How do you think the decider will go? Comments below…