"Four of the six groups are shaping as three-way battles, while the other two look more like two-way head-to-heads." Huw Richards reports

Halfway through, and the pool stage is beginning to take on significant shape.

Four of the six groups are shaping as three-way battles, while the other two look more like two-way head-to-heads.

Those groups also contain the two remaining unbeaten teams, each on course to reach the five-win tally that guarantees progression, even if you do not win the pool.

They may also be the likeliest to produce the teams who grab the best runners-up spots, as parity between contenders in other pools handicaps their chances.

Guinness Premiership teams maintained their dominance this week, with five wins out of seven - and one of the defeats was inflicted by another English club. Six of the seven are still in serious contention for a playoff place.

The epidemic of constipation that has afflicted the TOP 14 spread to the Heineken, with six French teams managing five tries between them - three scored by Clermont Auvergne.

And six teams have been definitively eliminated after failing to win any of their first three matches. Some could have been predicted. Viadana and Treviso sadly illustrate the continuing struggles of the Italian clubs.

Harlequins were always the weakest of the English septet. Edinburgh are in a brutally tough group and Ulster have always been prone to off-years - past winners they may be, but only Treviso have lost more Heineken ties.

Llanelli, though, even allowing for the quality of their group, are a genuine shock.

And it isn't even as though the Scarlets have got close.

Semi-finalists last season, this time they've lost both matches at Stradey by double figure margins and took a fearful hammering at Clermont.

Munster, taking revenge for last year's elimination at Stradey with a 29-16 victory plotted by the revitalised Ronan O'Gara, who kicked 19 points, also now lead their pool by a single point - the bonus they picked up in losing at Wasps - from the holders and Clermont.

They clashed in France, with Clermont winning a wild, fluctuating clash 37-27 with Brock James kicking 22 points and Aurelien Rougerie stealing Wasps' losing bonus with a last-minute try.

Mario Ledesma - whose form must have World Cup winner John Smit must wonder why he chose to sign for this particular club - was awarded a questionable score after reference to the video referee.

Ledesma was challenged by James Haskell, whose two tries playing at open side underlined the thought that he might end up challenging team-mate Tom Rees for that particular England shirt.

Wasps' victims in last season's final, Leicester, face an equally severe battle to qualify. They were made to look pedestrian at times by Toulouse, one French team who look decidedly unconstipated.

Yet, typically Leicester, they scored the only try through Ollie Smith and ground out a 14-9 win with Andy Goode kicking long and accurately to both touch and posts.

That pool's third force, Leinster, kept themselves in touch and eliminated Edinburgh with a 28-14 Friday night as Felipe Contepomi scored 18 points, but fell one try short of a bonus.

Scotland, though, retain an interest. Glasgow continue to impress and brought considerable pleasure to those exasperated by Biarritz's almost wilful refusal to play to anything remotely approaching their potential by sinking the boring Basques 9-6 at Firhill.

Biarritz had all the possession, but Dan Parks landed three penalties and endless handing errors did the rest.

Saracens, who now lead this group, will doubtless not mind even though they still have to visit Firhill. With Chris Jack making his Heineken debut they immolated Viadana 71-7 at Vicarage Road, Richard Haughton running in a hat-trick.

The final three-way contest saw another group of constipated Frenchmen, Stade Francais, squeeze out a 12-6 win over Cardiff, who had the considerable consolation of a bonus from a grim struggle.

Bristol have surprised even themselves by going so well and made short work of hapless Harlequins, whose coach Dean Richards reckoned to have seen the worst performance in his two and a half years in charge, 17-3 at the Stoop to stay well in touch.

London Irish may also be exceeding their own expectations as one of the two remaining 100 per cent teams.

They've still two away trips to come, but it is hard to believe they won't get the victory at Treviso and the home win over Newport-Gwent that would guarantee progression.

Their 24-16 win over Perpignan was based on line-out drives that brought two tries - one a contentious penalty-try - and 14 points from the boot of Peter Hewat, including the last-gasp penalty that denied USAP a crucial bonus.

USAP also had three sin-binnings, but before we indict 'French indiscipline', it should be noted that the first two were a South Africa and an Argentinian.

Newport-Gwent's 35-33 win in Treviso keeps them at least theoretically alive.

No doubt, though, about the outstanding performers so far. Gloucester made it three out of three, including two away wins, with a 31-7 thumping of Bourgoin on Friday night, with Ryan Lamb again outstanding and Andy Titterell claiming an injury-time bonus with their fourth try.

Only an extraordinary succession of back division injuries - with Olly Morgan, Mike Tindall, Iain Balshaw and Chris Paterson all forced off - clouds their immediate prospects.

Behind them the Ospreys can only go on winning and hope that they can overthrow Gloucester on the final weekend at the Liberty Stadium.

A 48-17 thumping of Ulster at the Liberty, Nikki Walker claiming two tries as they at last claimed a bonus, was a definite step in the right direction.