In the run-up to every UEFA Champions League draw, the focus is on which of the four seeding pots the 32 contenders will be placed in.
The system changed in 2015/16 with Pot 1 not decided by coefficients but rather consisting of holders Real Madrid and the champions of the seven top-ranked nations, including Leicester City. The other pots, as usual, are decided by coefficients, meaning Atlético Madrid, Borussia Dortmund, Arsenal and Sevilla are among those in Pot 2, Lyon will feature in Pot 3 and Beşiktaş in Pot 4, with the full line-up decided after the play-offs.
But how do the seedings actually influence things once the groups have been played? UEFA.com investigates, using every one of the 64 seeding pots consisting of eight teams apiece since the group stage expanded to 32 clubs in 1999/2000.
Reached next stage
Transferred to UEFA Cup/UEFA Europa League
Pot 1 – old system (holders + top coefficients)
1st: 72 teams from Pot 1 won their group (56%), 2nd: 38 were runners-up (30%), 3rd: 9 finished third (7%), 4th, 9 came fourth (7%)
Pot 1 – new system (holders + top coefficients)
1st: 4 (50%), 2nd: 4 (50%), 3rd: 0 (0%), 4th, 0 (0%)
Pot 1 – overall
1st: 76 (56%), 2nd: 42 (31%), 3rd: 9 (7%), 4th, 9 (7%)
1st: 35 (26%), 2nd: 51 (38%), 3rd: 30 (22%), 4th, 20 (15%)
1st: 15 (11%), 2nd: 26 (19%), 3rd: 53 (39%), 4th, 42 (31%)
1st: 10 (7%), 2nd: 17 (13%), 3rd: 44 (32%), 4th: 65 (48%)
(% may add up to 99 or 101 due to rounding)
• In 2002/03 seven sides from Pot 1 finished top of their groups, while each year from 2005/06 to 2008/09, and again in 2010/11, all eight went through.
• Last year too all eight teams in the new-look Pot 1 progressed. Of the four that would have been in Pot 1 under the previous systen (Barcelona, Chelsea, Bayern München, Benfica) three finished top.
• In 2004/05 five Pot 2 teams topped their groups, while in 2006/07 all eight went through, just as for Pot 1.
• Last season, under the new system, the pot included four teams that would previously been top seeded: both Madrid clubs, Porto and Arsenal. Three of those went through (as did Manchester City) but Porto were one of four in the pot to end third.
• In 1999/2000 three clubs won their groups while in 2014/15 a record six progressed, five as runners-up.
• In 2000/01 and 2001/02, and again in 2012/13, two of the eight came top. In 2001/02 a record four advanced to the next stage.
• Three sides failed to get through during the first 32-team season of 1999/2000, and in 2000/01 a record two teams ended up fourth.
• In 2012/13, five of the clubs in the pot failed to proceed to the knockout rounds. From five seasons up to 2014/15, as well as three seasons previously, two finished bottom.
• In 2006/07 all eight teams failed to survive the group phase, though only two were fourth, compared with five in 2003/04.
• 2013/14 was the fourth time (all in the past eight campaigns) when no sides went through, and the third occasion after 2006/07 and 2010/11 where six ranked last. Six teams also came bottom last season but Wolfsburg were top of their section and Gent second.
• Until Benfica in 2014/15, no club from Pot 1 had placed fourth since Manchester United in 2005/06; before that, at least one always had.
• Five of the ten instances of Pot 4 teams winning their groups came between 2000/01 and 2002/03. All five subsequent to that are since 2011/12.
• Last season Group F finished in seeding order (Bayern, Arsenal, Olympiacos, Dinamo Zagreb). Arsenal would have been in Pot 1 with Bayern under the old system.
• Twelve of the last 17 winners began the competition in Pot 1. The exceptions were AC Milan (2002/03, Pot 3), Porto (2003/04, Pot 2), Liverpool (2004/05, Pot 2), Internazionale Milano (2009/10, Pot 2) and Real Madrid (2015/16, Pot 2) – two of those sides were coached by José Mourinho, who has never got to the final from Pot 1. Real Madrid would have been in Pot 1 last season under the old system.
• Ten of the last 17 runners-up were in Pot 1. The exceptions were Valencia (1999/2000, Pot 3), Bayer Leverkusen (2001/02, Pot 3), Monaco (2003/04, Pot 4), Milan (2004/05, Pot 2), Borussia Dortmund (2012/13, Pot 4), Atlético Madrid (2013/14 and 2015/16, Pot 2) and Juventus (2014/15, Pot 2). Atlético would have been in Pot 1 last season under the old system.
• Seven finals (2000/01, 2005/06–2008/09 and 2010/11–2011/12) contained two top seeds. Three (2003/04, 2004/05 and 2015/16) featured none, though last season’s finalists would both have been in Pot 1 under the old system.
• Six of the seven finals that have gone to penalties in the past 16 years were between two teams from the same seeding pot (2002/03 the exception).