Top 10 clubs based on UEFA's 5-year ranking
UEFA assigns a coefficient to clubs based on their performances in European club competitions - the Champions League, Europa League and Europa Conference League - over a five-year period.
The coefficient is calculated by awarding points to clubs in the three aforementioned UEFA club competitions. For instance, every match win from the group stage onwards carries two points; a draw is worth one point, and so on.
Additional points are awarded to group winners and group runners-up, and for each round a club reaches beyond the Round of 16.
A club's five-year coefficient is the higher of the sum of points aggregated in UEFA club competitions in the previous five seasons or 20% of its association's five-season association coefficient.
On that note, here is a look at the top ten clubs in ascending order as per UEFA's five-season ranking after MD1 of the Champions League and Europa League:
#10 Manchester United - 91 points
Manchester United have been regulars in the UEFA Champions League, failing to qualify for the competition only twice this century.
In the two years they failed to qualify for the blue-riband competition of European club football, United made deep runs in the UEFA Europa League. They won the latter competition in 2016-17 and reached the semi-finals three years later.
Last season, United started their European sojourn in the UEFA Champions League. But they ended their campaign in the UEFA Europa League, losing to Villarreal on penalties in the final.
United kicked off their European campaign this season with a defeat at Swiss club Young Boys in their UEFA Champions League opener.
#9 Atletico Madrid - 91 points
Atletico Madrid have been regulars in the UEFA Champions League for almost a decade now. They have reached two finals in the competition, losing both times to Real Madrid, during this period.
The Rojiblancos have progressed beyond the group stage in all but one of their last nine UEFA Champions League campaigns. The only time they didn't do so (2016-17), they won the UEFA Europa League, beating Marseille.
Last season, Diego Simeone's men faced a surprise elimination against Leipzig. The La Liga holders were held to a goalless draw by Porto earlier this campaign before they racked up their first win of the season at AC Milan.
Note: Atletico's Milan win is not included in their points tally.
#8 Juventus - 93 points
Juventus have been UEFA Champions League regulars since 2012-13, reaching at least the Round of 16. The former champions have reached two finals during this period, but came up short on each occasion.
The record Serie A champions have failed to get past the Round of 16 in their last two appearances in the competition. Last year, Juventus were knocked out at this stage of the UEFA Champions League by Porto on away goals.
The Bianconeri opened their campaign in the UEFA Champions League with a win over Malmo this season.
#7 PSG - 98 points
Like Juventus, PSG have been regulars in the UEFA Champions League since the 2012-13 season, making at least the Round of 16.
The Ligue 1 giants have been a force to be reckoned with in Europe, especially in the last few seasons. In 2019-20, PSG were denied a continental quadruple when Bayern Munich beat them by a solitary goal in the final.
Last season, PSG eliminated the holders in the quarter-finals, but couldn't get past Manchester City in the last four. This year, they started their UEFA Champions League campaign with a draw at Club Brugges. PSG returned to winning ways with a home win over City on Matchday 2.
Note: PSG's City win is not included in their points tally.