It promises to be a tense weekend of Champions Cup action as Ulster aim to secure a quarter-final spot. Here's an overview of the current state of play and what we need to do...
Who can still qualify?
The five pool winners qualify automatically for the quarter-finals, with the four sides with the most points getting home advantage.
They will be joined by the three best second-placed teams.
Currently, 15 teams have a chance of qualifying.
The Pool leaders are Leinster, Clermont, Toulon, Ulster and Munster, while Scarlets, La Rochelle, Ospreys, Racing 92 and Exeter occupy the runners up spots.
All five teams in third place can also qualify, but require other results to go their way. These teams include defending champion Saracens, Montpellier, Bath, Castres and Wasps.
What if teams from different pools finish level on points?
If two teams are tied on points, the club with the best aggregate points difference from games in the pool stage will progress.
Failing that, the team with the most tries from the pool stage goes through. If that is equal, progression is decided by the club with the fewest number of players suspended. If they still cannot be separated, they will draw lots.
What if teams in the same pool are level?
If two teams in the same pool tie on points, their ranking is determined by the results of the two matches played between the sides in the pool stage.
The team with the most match points from the two games goes through. If equal, it goes down to the club with the best aggregate points difference from the two meetings.
Finally, it will come down to the side that scored the most tries in the two matches.
So, what do Ulster have to do?
Ulster travel to face Wasps, knowing that a bonus-point victory will confirm them as group winners regardless of La Rochelle's result against bottom side Harlequins.
La Rochelle will win the group if they win and Ulster lose, or if they can secure a bonus-point victory over ‘Quins and Ulster do not score four tries. That would leave both teams on 21 points, but the Top 14 side have a better match points haul from their two games against Ulster.
If Ulster lose (with or without a losing bonus point), they still have a chance to qualify for the last eight, but would be relying on other results going in their favour.
With Ulster’s game scheduled as the last game of the weekend (Sunday, 3.15pm), they will at least have the advantage of knowing what they have to do, having seen the results from across the other pools earlier in the weekend.
Who can still qualify?
The five pool winners qualify automatically for the quarter-finals, with the four sides with the most points getting home advantage.
They will be joined by the three best second-placed teams.
Currently, 15 teams have a chance of qualifying.
The Pool leaders are Leinster, Clermont, Toulon, Ulster and Munster, while Scarlets, La Rochelle, Ospreys, Racing 92 and Exeter occupy the runners up spots.
All five teams in third place can also qualify, but require other results to go their way. These teams include defending champion Saracens, Montpellier, Bath, Castres and Wasps.
It's all to play for this weekend!
— Ulster Rugby (@UlsterRugby) January 19, 2018
Here's how the teams rank ahead of the @ChampionsCup Round 6 fixtures ? pic.twitter.com/irrXW1GDu1
What if teams from different pools finish level on points?
If two teams are tied on points, the club with the best aggregate points difference from games in the pool stage will progress.
Failing that, the team with the most tries from the pool stage goes through. If that is equal, progression is decided by the club with the fewest number of players suspended. If they still cannot be separated, they will draw lots.
What if teams in the same pool are level?
If two teams in the same pool tie on points, their ranking is determined by the results of the two matches played between the sides in the pool stage.
The team with the most match points from the two games goes through. If equal, it goes down to the club with the best aggregate points difference from the two meetings.
Finally, it will come down to the side that scored the most tries in the two matches.
So, what do Ulster have to do?
Ulster travel to face Wasps, knowing that a bonus-point victory will confirm them as group winners regardless of La Rochelle's result against bottom side Harlequins.
La Rochelle will win the group if they win and Ulster lose, or if they can secure a bonus-point victory over ‘Quins and Ulster do not score four tries. That would leave both teams on 21 points, but the Top 14 side have a better match points haul from their two games against Ulster.
If Ulster lose (with or without a losing bonus point), they still have a chance to qualify for the last eight, but would be relying on other results going in their favour.
With Ulster’s game scheduled as the last game of the weekend (Sunday, 3.15pm), they will at least have the advantage of knowing what they have to do, having seen the results from across the other pools earlier in the weekend.