CSKA Moscow's defender Vasily Berezutskiy (L) and Bayern Munich's Dutch midfielder Arjen Robben vie for the ball during the UEFA Champions League Group E second-leg football match FC Bayern Munich vs CSKA Moscow in Munich, southern Germany, on December 10, 2014. Bayern Munich won the match 3-0.GUENTER SCHIFFMANN/AFP / Getty Images
With nine different winners in the past 11 years, no one could ever accuse the Champions League of being predictable.
It does appear, however, that an established "Big 4" has been created in Europe's premier club competition – and this year's group stage backs up the theory.
Barcelona, Chelsea, Bayern Munich and Real Madrid, the past four winners of European club soccer's top prize, were the top teams in group play, which finished Wednesday. In each of the past three seasons, at least three of that quartet has reached the semi-finals of the Champions League. Real and Barca did so in 2011, too.
So, heading into the knockout stage that kicks off in February, it would be a big surprise if this season's champion didn't come from this small pool of juggernauts – teams who currently are playing soccer at another level to the rest.
"Everybody's there, so the Champions League starts now," Chelsea manager Jose Mourinho said of a last-16 lineup that contains 11 of the teams who advanced in the 2013-14 season.
No club has ever successfully defended the Champions League title since the competition's inception in 1992. Could Real be about to end that jinx?
At top of the Spanish league, a team boasting the attacking talents of Cristiano Ronaldo, Gareth Bale, James Rodriguez and Karim Benzema was the only one to pick up a maximum 18 points in the group stage. Real has won its past 19 games in all competitions and Ronaldo, the reigning world player of the year, has already reached 30 goals for the season. "I know I've got an extraordinary team," Real coach Carlo Ancelotti said after Tuesday's 4-0 win over Ludogorets Razgrad. "I don't tire from saying this."
Any side that contains Lionel Messi will always have a great chance, and Barcelona will be expected to reach the semi-finals after missing out last season. Barca's defence remains a concern – although it has only conceded seven goals in 14 games in the Spanish league – but Wednesday's 3-1 win over Paris Saint-Germain at Camp Nou gave a taster of what to expect from its expensively assembled, all-star attack.
Messi – with his record-extending 75th Champions League goal – was on the score sheet along with Neymar and Luis Suarez. The trio is six weeks into its new partnership and when the last 16 comes around it could be unstoppable.
Bayern's only defeat in a tough-looking Group E came at Manchester City after playing more than 70 minutes with 10 men and conceding twice in the last five minutes to lose 3-2. The German champions have few weaknesses in their team, with their attack looking even stronger with the addition of Robert Lewandowski and have a coach in Pep Guardiola, who has gone all the way before in the Champions League, with Barcelona in 2009 and '11.
Chelsea, meanwhile, has found a cure to its attacking frailties of last season with the signing of Spain striker Diego Costa and was the top-scoring team in the group stage. Traditionally strong in defence, Eden Hazard is developing into one of the world's best wingers and Cesc Fabregas has brought more creativity into the team's midfield.