Despite facing tricky away ties in Round 6, Toulouse, Northampton, Leinster and either Leicester or Perpignan (due to try count) are likely to secure home advantage albeit Leicester and Ulster will need to score plenty of tries both against Italian opposition to win their respective pools.

The Scarlets have a chance to upset the applecart but need to beat Perpignan away, to qualify most likely behind Leicester as a best runner up, who finish at home to Treviso. Bath and Clermont also have very outside chances of making the final eight.

Amlin Challenge Cup
The Amlin Challenge Cup Quarter Finalists comprise the five pool winners from the group stage plus three teams that miss out on Heineken Cup knockout stage:
Pool 1) Harlequins or Bayonne. Harlequins play Bayonne at The Stoop, winner goes through, unless Quins lose with a bonus point and Bayonne only get 4 points for a win, in which case Quins would top the pool.
Pool 2) Brive
Pool 3) Montpellier / Exeter. Montpellier play Exeter at home, winner goes through
Pool 4) Stade Francais Paris
Pool 5) and the fifth Amlin Cup pool winner looks certain to be La Rochelle as they play at home to Rovigo who are yet to pick up a point in the group phase.

The Quarter Final draw is completed with three Heineken Cup runners up, which makes the situation rather more complex.

With Heineken Cup pools 4 & 5 seeming certain to produce the Heineken Cup quarter finalists, the shape of the other four pools are likely to produce any of the below qualifiers:

Pool 1) Castres Olympique/ Cardiff Blues. The Blues on 10 points need to win in Edinburgh and hope Northampton, chasing a home Quarter Final which a win will secure them, beat Castres (11 points) in France. The final penalty at Cardiff City Stadium gave Castres a bonus point in defeat and keeps them second in the pool ahead of the Blues by one point.

However, although the aggregate scores between the teams are also in Castres' favour, if the Blues and Castres finish on equal points in the group, the Blues will have the advantage as they have scored more tries in the two head to head meetings. This is the first deciding factor in the pool stage before aggregate scores are considered.

Pool 2) Clermont. Currently on 14 points, Clermont play Saracens away on Friday, and need a win to secure an Amlin QF, any defeat could open the door to another team. Racing can't catch Clermont due to the results between the two teams.

Pool 3) Munster / Ospreys. Both teams are at home for the final group games, Ospreys (10 pts), are at home to group winners Toulon, who are unlikely to get a home QF regardless of the score, so will want to finish with a flourish at the Liberty however, Munster (11 pts) are in the box seat, needing a bonus point win against London Irish or to better the Ospreys result, to give them the runners up spot and a likely Amlin QF.

Pool 6) London Wasps (15 pts) could still qualify for the Heineken Cup, if they beat Toulouse at Adams Park, and if Leicester lose to Treviso or Ulster lose to Aironi & Biarritz lose to Bath.

Pool 5) If the Scarlets win in Perpignan, and Leicester lose to Treviso, the Tigers could drop into the Amlin Challenge Cup positions and likewise, if Bath beat Biarritz and/or Ulster fail to beat Aironi, either Ulster or Biarritz could end up playing Amlin Challenge Cup rugby in the knockout stages.

Cardiff Blues Qualification Scenarios
For Cardiff Blues to qualify for the Amlin Quarter Finals they first need to beat Edinburgh at Murrayfield (last achieved March 2008) and then better the result Castres get against Northampton. If Castres win without a bonus point, the Blues need to win with a bonus point. Again if Blues and Castres finish on equal points in the pool, the Blues will be placed higher as a result of scoring more tries than they have conceded against Castres.

The most likely successful qualification scenario is arguably:
A) Clermont to lose away to Saracens, with or without a bonus, ideally without.
B) Northampton to beat Castres in France.
C) Cardiff Blues to beat Edinburgh, needing at least a bonus point win if Clermont get a losing bonus.