So complex is the qualifying picture prior to this weekend's final round of pool matches in the Heineken Cup, that tournament organisers furnished all participating outfits with a reminder of the qualifying criteria for the quarter-finals in the last 48 hours. And even then, if you're not confused you still haven't a clue as to what's going on.

The six pool winners (ranked 1-6) and the two best runners-up (7-8) will advance to the last eight, where the top four ranked sides (based on match points accrued - two for a win, one for a draw) will have home advantage on the following basis: 1 v 8, 2 v 7, 3 v 6, 4 v 5.

As things stand, Toulouse and Munster have not only won their pools, but have assured themselves of home quarter-finals - though their ranking has still to be decided. Northampton too, cannot be overhauled in Pool Six, and are assured of a place in the last eight, as are Wasps in Pool Three, though whether as pool winners or runners-up is still dependant upon their result away to Llanelli, the second-placed side in the group.

Theoretically, there are another 14 teams who are mathematically still in contention for a last eight place, although in reality this can be trimmed down to about eight who have credible chances of making the quarter-finals, one of whom are Leinster.

In the event of a tie between two or three teams in the same pool, their pool ranking will be determined by the following criteria in this order:

(i) - the respective points aggregate in the matches between the two or three clubs.

(ii) - the number of tries scored in the matches between the sides.

(iii) - the number of tries scored in all six pool matches.

(iv) - the aggregate points difference in all six pool matches.

(v) - the fewest number of players sent-off in all pool matches.

(vi) - toss of a coin.

In the event of a tie between all four teams in a given pool (applicable only in Pool One), the final pool ranking will be decided by the following criteria in this order:

(i) the respective points aggregate in all pool matches.

(ii) the number of tries in all pool matches.

(iii) the least number of players sent-off in all pool matches.

(iv) toss of a coin.

When it comes to determining the ranking of the respective pool winners and pool runners-up (i.e. 1 to 8), in the event of teams not in the same pool having the same number of match points the following criteria will be applied in this order:

(i) the number of tries scored in the whole pool programme.

(ii) the points aggregate from all pool matches.

(iii) the fewest number of players sent off in all pool matches.

(iv) toss of a coin.

After ten home wins out of ten thus far, an away victory for Stade Francais in Hughendon tonight would assure them of first place (and in the process extinguish Leinster's chances of topping the pool) as Stade have a 62-30 aggregate lead in their head-to-heads with Mike Ruddock's team.

A defeat for Stade tonight would greatly simplify and enhance the situation for Leinster, for whom victory at Welford Road would then give them first place in the group. However, a Stade win tonight means Leinster's only chance of reaching the last eight would be to beat Leicester (which they must do to have any chance of progress) and hope they can obtain one of the two best runners-up slots.

The three threats to Leinster in this scenario come from pools three, five and six, and Leinster would need to finish above at least two of them in the ranking. For example, Leinster would need Wasps to beat Llanelli in Pool Three, leaving Llanelli as runners-up and also with eight points, while Leinster themselves score four more tries than Llanelli do against Wasps in the process of beating Leicester.

To finish above the Pool 5 runners-up, Leinster would need Cardiff to lose away to Harlequins or Montferrand to lose at home to Treviso - which is unlikely. Alternatively Leinster could finish above Montferrand by scoring four more tries than the French club do, although aside from having the easier looking fixture, Montferrand also have the advantage of playing a day later.

To finish above the likely Pool 6 runners-up, Edinburgh Reivers, Leinster must beat Leicester and hope that Edinburgh either lose in Grenoble, or score less tries than Leinster do.

Toulouse are already through as pool winners, and guaranteed a home draw. Realistically Bath must beat Toulouse and in the process enhance their try tally in the hope that they garner one of the two best runners-up slots. The Padova-Swansea game is purely academic.

Tonight's game in Ravenhill is purely academic but everything is on the line in Stradey Park tomorrow. Wasps are already in the last eight, and based on their earlier 22-13 win over Llanelli, anything better than a nine point defeat tomorrow will ensure them a home quarter-final.

For Llanelli, victory by ten points or more would propel them to first place and earn them a home quarter-final, while a win by less than that would earn them one of the two best runners-up places. Thus, a mutually beneficial Llanelli victory by less than nine points would put both clubs through.

However, a Wasps win would leave Llanelli on the eight-point threshold for one of the two best runners-up slots; their prospects then resting on their try tally.

The most clear-cut of the groups, with Munster already assured of first place and a home quarter-final. Another victory today is liable to earn them a ranking of two (presuming Toulouse also beat Bath) and a home quarter-final against the best runners-up, most probably Llanelli or Wasps from Pool three, or alternatively Montferrand from Pool 5.

Were a win in Ponty accompanied by a Toulouse defeat, they could be ranked one, in which case Munster would be at home to the second placed runner-up (one of the aforementioned trio or, at a push, possibly even Leinster). A ranking of 3, on the basis that Munster lose today or Wasps overhaul them on try count, would pit Declan Kidney's team against the sixth ranked pool winners, most probably Stade Francais or, at a push again, Leinster.

The inequity of not having all 12 games kicking off simultaneously is best highlighted here, where come kick-off on Sunday Montferrand will know exactly what is required of them to secure one of the two best runners-up slots.

Victory for Cardiff at Quins would assure them of first place, while defeat would probably put them out and leave the door ajar as pool winners for Montferrand. However, in the event of a Cardiff win, Montferrand will know from the previous day's results how much they need to boost their healthy try tally to supplant the other runners-up in the rankings on eight points.

Even in defeat, and coupled with an Edinburgh win, Northampton cannot be overhauled because of their two wins over the Scots, while a win for Northampton would earn them a home quarter-final.

Like Leinster, Edinburgh need to beat Grenoble and boost their try tally in the hope of claiming a best runners-up slot.