The quarter-final picture is becoming clearer as the European Champions Cup heads into the fourth round of pool stage matches, but plenty of questions still remain.
Some of those are likely to be answered following this weekend's games, with the six taking place on Saturday all having plenty riding on them as the pool stages pass the halfway point.
Here, we take a look at some of the big talking points ahead of Saturday's matches…
Anglo-Irish clashes could be decisive
Last Saturday saw Ireland's two powerhouse provinces triumph against Gallagher Premiership opposition to lay down a marker in their respective pools and they will be aiming to do the same this weekend.
The most eye-catching was Leinster's 43-16 win away to Northampton Saints in Pool 1, with the hosts' head coach Chris Boyd referring to their opponents' performance as "near Test-match level".
Now Boyd's men face the onerous task of going to Dublin needing to win to stay in with a realistic chance of topping the pool, plus maintaining their current place as one of the three second-placed teams who will qualify for the knock-out stages.
But this match comes six years to the day since the Saints turned the tables on Leinster to triumph 18-9 at the Aviva Stadium after being humbled 40-7 the previous week.
Current squad members Tom Collins, Alex Waller, Mikey Haywood and Tom Wood - plus the injured Courtney Lawes - were all involved in that memorable win too, so will no doubt be able to provide some insight to their team-mates on how to beat Leo Cullen's side on their home turf.
Munster, meanwhile, were involved in a much closer-fought contest at home to Saracens last weekend, grinding out a 10-3 victory over Saracens at Thomond Park in the driving wind and rain.
That kept them just one point behind Pool 4 leaders Racing 92, although earning a losing bonus point means Sarries are still firmly in the hunt for a place in the knock-out stages.
Ensuring their place in the Premiership following their points deduction may be the priority this season for Mark McCall's men, but that has not stopped him again naming a strong side as the defending champions welcome the two-time winners to Allianz Park.
England captain Owen Farell, the Vunipola brothers, Jamie George, Vincent Koch, George Kruis and Elliot Daly all start in a team which also sees Max Malins and Joel Kpoku make their first European starts
Plenty to play for in Pool 5
Although French champions Toulouse seem to be sailing through to the knock-out stages with three wins from three, the other three teams in the pool still have a possible place the quarter-finals up for grabs.
Gloucester lead the charge with seven points, with Montpellier two behind them and the Cherry and Whites' weekend opponents Connacht on four points at the bottom of the pool.
Connacht kicked off their return to European club rugby's premier competition with victory over Montpellier at home, but then lost away to Toulouse and were beaten 26-17 at Kingsholm last Sunday.
The rematch with Gloucester in Galway this Saturday has become pivotal for both teams' chances of keeping their qualification hopes alive, with the three bonus points the visitors have picked up so far already giving them an advantage over their rivals.
Defeat for Andy Friends' side would all but end their hopes of a quarter-final place and the head coach's task is not helped by being without nine players due to injury, including back row star Colby Fainga'a.
Victory for Gloucester in the early afternoon match would put them in a good position ahead of the final two games against the pool's French teams in January. Meanwhile, those two play each other later in the day in Montpellier.
Warriors on the march?
Glasgow Warriors' adaptability came to the fore last weekend as they fought back from five points down at half time to record a 27-24 win away to La Rochelle.
Head coach Dave Rennie put the turnaround down to a shift in tactics, adopting a more direct approach after the break rather than continuing with the expansive manner which had not worked for them during the first 40 minutes.
"What we found in the second half, when we were more direct and went multi-phase, is that we put them under a lot more pressure, which is something to think about for next week," Rennie said in the wake of that win.
Making it back-to-back wins over their French Pool 2 rivals would keep Glasgow firmly in the hunt for their third quarter-final appearance in four seasons - although the previous two occasions have seen them bow out to Saracens.
It is fair to assume Rennie, who is leaving the 2019 PRO14 runners-up at the end of this season to take up the role as head coach of the Australia national team, would dearly love to go away with a trophy from his time at the Warriors.
It is far too early to even consider the possibility of them becoming the first Scottish side to lift the Champions Cup, but getting through to the last eight again would at least mean Glasgow could start to dream of an unlikely European triumph.