Leinster Rugby host Stade Toulousain on Saturday and Stade Rochelais welcome Exeter Chiefs on Sunday. The four sets of analyst teams will have been preparing for these matches since the quarter finals wrapped up at the start of April.

Powered by Oval Insights’ data, Sam Larner breaks these contests down into one key battle in each contest.

Leinster v Toulouse

Toulouse have perhaps rugby’s most potent weapon in Antoine Dupont. Arguably the best scrum-half in the world, he has lost just one of the 21 matches he has started this season: against Ireland – World Rugby’s number one ranked team – in Dublin.

Last season, he lost just five matches he started. A fantastic win rate, no doubt, but again two of those losses came against Irish provinces in Leinster and Ulster Rugby. He doesn’t lose often, but when he does, odds are an Irish side are involved.

This issue seems to afflict the Toulouse side as a whole. They have waltzed through the Heineken Champions Cup this season, scoring 27 points or more in every match and boasting a handsome points difference of 115.

However, their combined points difference against Munster Rugby in the pool stage was just nine – a far cry from their other romping performances.

In total, Munster kept Toulouse to just five clean breaks in total. No other opponent kept them under seven across 80 minutes this season. What is their secret?

Defences pride themselves on forcing attacks to go around them. It’s like a game of tennis – just keep getting the ball back for your opponent to make a mistake. In rugby, keep forcing the attack to make the next pass. The above is an example of how Dupont can hurt you if you fail to properly defend those channels around the ruck. However, on the whole, Munster did a great job of taking this attacking weapon away from Toulouse.

Notice how Munster batten down the hatches around the ruck in these consecutive phases. This eventually forces Toulouse to revert to a more easily defendable attack, the sort that they have defended against time after time.

Prioritising narrow defence mitigates Dupont’s extraordinary threat in and around the breakdown and forces Toulouse to play their – albeit still impressive – wider game.

That is the key to beating the French giants. You can’t be alert to all of Toulouse’s weapons all of the time; what you need to do is prioritise stopping their most lethal threats.

If you stop Dupont from scurrying through your defence, you do more than most teams. The key to beating an opposition is to force them to do something unfamiliar to them.

For Toulouse, that’s attacking without Dupont as the focus. Leinster’s physical defence and ability to hold the ball for long spells of possession could well starve their opposition of opportunities and frustrate Toulouse’s talisman this Saturday.

Stade Rochelais v Exeter Chiefs

La Rochelle and Exeter have more in common than both being located near water in the west of France and England respectively; they are top of the TOP 14 and Gallagher Premiership in terms of total carries.

In recent seasons, teams have developed a preference for playing with less possession. However, Ireland’s success in the Six Nations and Leinster, La Rochelle and Exeter’s in EPCR competitions represent a different school of thought in the game.

Exeter’s league season has been a mixed bag – they will not appear in the playoffs of the Premiership – but they have a great opportunity to beat La Rochelle and progress to the Heineken Champions Cup final.

La Rochelle have lost eight matches in the TOP 14 this season. Three of these losses have come when they have been starved of carries - La Rochelle average three points fewer per match when they make fewer than 110. Their way to win is to hold onto the ball.

Once again, the key to beating them is to force them to revert to an unfamiliar gameplan.

Gloucester Rugby are the team who’ve stretched La Rochelle the most so far in the Heineken Champions Cup. In the Round of 16 contest, it wasn’t the English club’s ability to starve La Rochelle of possession that put them in contention, though, it was the quality of their wide attack.

Look how keen Gloucester were to shift the ball wide and as early as possible. They wanted to force La Rochelle’s pack to charge all over the pitch. This allowed Gloucester to carry into space and simultaneously test the fitness of the giant La Rochelle pack, diminishing the impact they could have in the carry when they won back possession.

Whilst Gloucester missed out on the win, their strategy worked for long periods of the match. La Rochelle conceded 26 points for just the seventh time this season.

To go better than Gloucester, Exeter will have to learn from their domestic rivals and add another layer to their attack. They have to find a way to not only stretch La Rochelle’s defence, but also starve them of possession. So far, no team has managed to do that, but the Chiefs are more adept than most at a possession-heavy gameplan.

The most important weekend of the Heineken Champions Cup season so far is almost upon us.