It hasn’t been a vintage Investec Champions Cup pool stage, but there will be plenty on the line for Leinster and Munster, as one looks to secure a top seed for the knockouts, and the other simply hopes to qualify for the Round of 16.
With that in mind, here’s how the two provinces are looking heading into the final round of games.
Naturally, the various bonus-points at stake means there are simply too many permutations to go through individually, so we’ve picked out the obvious ones.
The key things to remember are four points for a win, two for a draw, and a bonus-point for scoring four tries and / or for losing by seven points or less.
The top two sides in each pool will have home advantage in the Round of 16, where they will host the third and fourth-place teams.
And the higher your overall seed is in the competition, the longer you get to stay at home.
Leinster
Saturday’s bonus-point win for Leinster against La Rochelle has guaranteed a place in the knockout stages for Leo Cullen’s side, with this Saturday’s away trip to Bayonne all about securing one of the top seeds for the Round of 16 and beyond.
Pool 3
The top two in each pool will have home advantage for their first knockout game, something Leinster will guarantee if they pick up even a losing bonus point in the south of France.
The only way Leinster can fall out of the top two in their pool would be if they lose without a bonus-point, while Harlequins would have to win away to La Rochelle, and Stormers would have to beat Leicester Tigers with at least four tries, while also overturning a 47-point differential.
With three wins from three so far, Leinster will have a keen eye on picking up as high a seed as possible, keeping them at home for as long as they remain in the competition.
Through three games, the province are the fourth-ranked team overall in the competition (14 points), meaning they would have to climb above two of Bordeaux-Begles or Glasgow Warriors (15) and Bristol Bears (14, but ahead of Leinster on points difference) if they are to break into the top two, which would give them home advantage right through to a potential semi-final.
Pool 1
Securing one of those top two seeds is not in Leinster’s hands.
If Glasgow and Bordeaux both pick up bonus-point wins against Saracens and Bristol, then Leinster can’t finish higher than third in the knockout seedings.
If either (or both) of those sides win without a bonus this weekend, then a bonus-point win for Leinster against the already eliminated Bayonne should be enough for them to finish as one of the top seeds.
With Bordeaux (15pts) away to Bristol (14pts), and both teams having a strong points difference, either of those teams could finish ahead of Leinster in the overall standings with a bonus-point win of their own.
A Glasgow defeat – or draw – at home to Saracens in Pool 1 would allow Leinster take one of the top overall seeds with a win in France.
Pool 1
Munster
The stakes are high, and the scope is wide for Munster, as they prepare to welcome old rivals Castres to Thomond Park for what is a record 20th meeting of the two teams in this competition.
Last weekend’s late defeat to Toulon in France has raised the pressure on the province, although by the same token, their late defensive stand to earn a bonus-point and deny Toulon a BP of their own, may well prove vital.
Pool 2 is the most tightly packed of the bunch, so every range of outcome is on the cards, from a home Round of 16 game, to finishing bottom of the pool.
Let’s start with the simple equation: If Munster lose to Castres, they are out, either dropping into the Challenge Cup, or finishing bottom of the pool.
If they draw and match their opponents for any bonus-points in that game, they will also need Gloucester to lose or draw against Toulon at Kingsholm.
Technically, Munster could be eliminated even with a win this weekend.
Pool 2
If Clayton McMillan’s side beat Castres without a bonus point, and if Edinburgh pick up at least one point against Bath (Friday 8pm), then they could be knocked out if Gloucester defeat Toulon (Saturday 8pm) by seven or fewer points, and if both teams score at least four tries along the way.
If Toulon defeat Gloucester, then a win of any kind would be enough for Munster to qualify, although they would be away from home in the next round.
With pool leaders Bath and Edinburgh meeting at The Rec on Friday evening, there is an outside chance that Munster could break into the top two, which would be enough for a home game in the Round of 16.
First, they would likely need a bonus-point win against Castres, which would bring them up to 11 points, while they would also need Gloucester to defeat Toulon by a low enough score so as not to leapfrog Munster on points difference.
As well as that, they would need a favourable result between Bath and Edinburgh; a one-sided win for either of those teams would leave room for someone else to break into that top two.
Simple, really!
Follow a live blog of Munster v Castres (Saturday 5.30pm) on rte.ie/sport. Listen to live radio commentary on Saturday Sport on RTÉ Radio 1.