The Champions League is the most prestigious club competition in European football. It is contested by the national champions (and, for some countries, one or more runners-up) of each member association and features the top sixteen clubs in Europe based on their domestic league rankings.
Teams play six matches in the group stage, three home and three away. Teams are ranked on their record in the group, with points awarded for wins and losses; draws count as half-points. Teams that finish first and second in the group advance to the knockout phase, while third place is eliminated. The winners of the tournament are awarded a trophy, which can be kept permanently by the club that wins it five times in a row or three times in a calendar decade.
The most successful club is Real Madrid, who have won fifteen titles (European Cup and Champions League combined). Liverpool, Manchester United, Bayern Munich, Juventus, Barcelona, Ajax and Valencia all have two or more Champions League titles.
Until 2008, the highest-ranked clubs entered directly into the group stage, while other clubs competed in a series of qualifying rounds. In addition to sporting criteria, a license must be obtained from the club’s national association in order to participate in the Champions League.
UEFA has changed the way it determines which teams get home advantage in the knockout phase of the competition, beginning this season. Instead of a random draw, teams that finish first in their groups will be guaranteed to have the second leg of their quarterfinals and semifinals at home. The rest of the seeds will be determined based on the result of the second round of the group phase, which takes place on Feb. 27.