The greatest teams ever
Barcelona have taken a record 52 points from the first half of the season, winning 17 out of their 19 games in La Liga.
In Lionel Messi, Xavi and Andres Iniesta, they boasted all three shortlisted players for the FIFA Ballon d'Or and the current side, including the Champions League-winning predecessors of 2006 and 2009, are now certain of their place in the pantheon of the all-time great teams.
ESPNsoccernet selects a list of some of the greatest sides of their eras.
Courtesy of their chairman Major William Sudell, a cotton mill owner, Preston became the dominant force in English football as an array of superior Scottish talent arrived at the club to be given part-time jobs in the mill and payment for performances.
They had been thrown out of the FA Cup for having professional players on the books in 1884, but professionalism was legalised the following year. It facilitated the birth of the famous 'Invincibles' side that went unbeaten throughout the inaugural season of the English Football League as well as winning the FA Cup without conceding a goal.
They retained the title the following year, but the team would deteriorate as players moved on and Sudell, in 1895, was imprisoned after embezzling funds from the mill.
The great Italy side that won the 1934 and 1938 World Cups and 1936 Olympics owed much to Vittorio Pozzo. He had taken charge of Italy for the 1912 Olympics, as well as stints with Torino and AC Milan in the '20s, before taking time out of the game following a bereavement.
When Benito Mussolini asked Pozzo to return to football to coach the national team in the late '20s, he agreed on condition that, distinct from the committee selections prevalent among international rivals, he be allowed complete control.
As well as featuring perhaps the greatest player of the age, Giuseppe Meazza, Pozzo supplemented his team with oriundi - Latin Americans of Italian heritage - including former Argentina internationals Raimundo Orsi and Luis Monti. "If they can die for Italy, they can play for Italy," Pozzo said.
There remain reservations about the team - their sometimes brutal style of play and explicit support of the Fascist regime - but there can be no doubt over their quality.
Sweden, who along with Ireland, Portugal, Spain and Switzerland managed to remain neutral throughout World War II, undoubtedly reaped the benefits on the football field. However, with the great Gunnar Gren and Gunnar Nordahl both establishing themselves at international level at the start of the '40s, there is little question that it was the birth of a genuinely great team.
They rose to international prominence in 1942 with a victory over a Germany side that, with the annexation of several Austrian and Polish players, had formed part of the Nazi propaganda machine for some time. Adolf Hitler had not been a huge fan of football, and Joseph Goebbels wrote that the Fuhrer had been "very agitated" after witnessing Germany's 2-0 defeat to Norway at the 1936 Olympics, so it was imperative the side did nothing to discredit the notion of the superior race.
After a 2-1 defeat in Switzerland in 1941, Goebbels had made clear there were to be no more embarrassments and that the players would be sent to the Eastern Front should they lose again. A 1-1 draw with Spain followed before Germany secured comprehensive victories against Hungary, Bulgaria and Romania.
However, in front of 98,000 fans in Berlin, they were defeated 3-2 by Sweden in September 1942. Germany won all three of their remaining games in 1942, but the unpredictability of results saw the team dissolved for the rest of the decade and the players sent to the front line.
Sweden, though, continued to grow as a team and won 19 of the 27 matches that followed, averaging four goals a game. Nils Liedholm began playing for the team in 1946 and they would claim a thoroughly deserved success at the 1948 Summer Olympics in London. However, as Gren, Nordahl and Liedholm joined AC Milan to form the legendary Gre-No-Li trio, their status as professionals meant they were no longer eligible to play for Sweden. Nordahl, Milan's all-time leading scorer, netted 43 goals in 33 appearances for Sweden.
The legendary Marvellous Magyars, led by the spectacular Ferenc Puskas with the able assistance of the likes of Sandor Kocsis and Nandor Hidegkuti, went 30 matches unbeaten following a 5-3 defeat to Austria in 1950. The run included two famous thrashings of England as well as victory in the 1952 Olympics.
It was brought to an abrupt end in the 1954 World Cup final as a West German side, beaten 8-3 by Hungary in the group stage, won 3-2. Puskas had missed most of the tournament through an ankle injury picked up during the first game against the West Germans and, though he scored the opener as Hungary went two goals ahead inside eight minutes, he was far from fully fit and one of the all-time great teams would go home without the trophy.
A recent study claimed the German team may have benefitted from the injection of illegal substances. "There are several strong indications that point to the injection of [methamphetamine] pervitin in some Germany players and not vitamin C as it was claimed," sports historian Erik Eggers said. "What is suspicious is that these injections to German players were distributed secretly and the only reason they became known was because those who got injected contracted jaundice. The most important indication, though, is that vitamin C is not injected."
Hungary bounced back from the defeat and immediately went on an 18-match unbeaten run before the team was broken up by the after-effects of 1956's 'Hungarian Uprising'.
Real Madrid (1955-60)
Real Madrid, with the legendary Alfredo Di Stefano at the heart of their success, won the European Cup in each of its first five seasons.
The rule at the time - though it was soon to be ditched - prevented teams fielding more than one foreigner and Di Stefano, an Argentina international, had taken up Madrid's slot. Nonetheless, he was to be assisted during that first European Cup success by the great French playmaker Raymond Kopa, a £50,000 signing from Rheims, as Di Stefano was naturalised as a Spaniard.
The duo were a key part of Madrid's success over the coming years, along with the likes of Francisco Gento, and during this time they also clinched league titles in 1955, 1957 and 1958. Ferenc Puskas joined the team in 1958 and, while he was injured for the 1959 European Cup success, he scored four goals as Madrid beat Eintracht Frankfurt 7-3 in the 1960 final.
Brazil had been thrown into chaos in March 1970, two months before the World Cup, when coach Joao Saldanha was sacked. A journalist by trade, he had delivered comfortable victories in each of his six games in charge, but Antonio do Passo, chairman of the committee making the decision, said he lacked the emotional stability for the job. That Saldanha had brandished a revolver when criticised by Flamengo coach Dorival Yustrich was, perhaps, testament to that fact.
Mario Zagallo, a player in the 1958 and 1962 World Cup triumphs, took charge of a team featuring Pele - whom Saldanha had labelled unfit prior to the tournament - alongside Jairzinho, Rivelino, Tostao and Gerson.
They were phenomenal in Mexico, sweeping to success as they won each of their six games, beating Italy 4-1 in a final that had been billed as the world's greatest attack against the world's greatest defence.
Rinus Michels, in charge of Ajax between 1965 and 1971, was the architect of the Total Football that brought Ajax three successive European Cup victories.
"People talk of Total Football as if it is a system," Ajax midfielder Arie Haan explained in 1973. "It is not a system. As it is at any moment, so you play. That is how we understand."
Ajax had reached the European Cup final of 1969 but, with Johan Neeskens joining Johan Cruyff, they clinched the trophy for the first time in 1971.
Michels walked out to join Barcelona later that year, but Istvan Kovacs took charge and continued the philosophy. They won the league title, European Cup, KNVB Cup, European Super Cup and Intercontinental Cup in 1972 and were then crowned European champions for the third time in succession in 1973 before Kovacs opted to return to his native Romania.
Ajax president Jaap van Praag, speaking about Michels' departure prior to the '73 final, said: "It was sad, but we all got together with the players and decided who we would like to be the new trainer. It was Kovacs. Naturally one must have a good man in charge of the team, but the team must reflect all the club and not him alone."
Rinus Michels agreed to take charge of the Dutch national team while still in his role with Barcelona, and his 1974 World Cup team is - along with Hungary - considered the finest not to have won the tournament.
Cruyff, who by that point had joined Michels at Barca, credited the coach with the transformation of the team: "Everyone in Holland wanted to say how the team should play, but he refused to have anything from outside interfering with the team. Suddenly there was one boss. He made the discipline and the tactics. We knew we had the gifts to be a great team, and this maybe was the only chance to show how great it could be."
Netherlands finished first in both their first and second group at the World Cup - thrashing Argentina 4-0 and beating a highly-rated Brazil team 2-0 along the way - but they came unstuck against West Germany in the final. The German newspaper Bild famously published a picture of the team frolicking with women under the headline 'Cruyff, Champagne, naked girls and a cool bath' and, although Netherlands were ahead before their opponents could touch the ball, they became overconfident and ended up losing 2-1.
"We wanted to humiliate the Germans," winger Johnny Rep said. "We started knocking the ball around and we forgot to score a second."
Bayern Munich (1974-76)
Just as West Germany stole Netherlands' glory at the World Cup, Bayern Munich were to become the new kings of the European Cup. Without Cruyff, Ajax were eliminated in the second round of the 1973-74 tournament and Bayern took up the mantle.
Franz Beckenbauer, their inspirational captain, had been an 1860 Munich fan as a child but, after a fractious encounter with the team during his time as a youth with SC Munich, he opted instead for Bayern. Along with the likes of Gerd Muller, Franz Roth and Sepp Maier, he began his career with Bayern in the mid-60s.
Bundesliga winners in 1972, 1973 and 1974, Bayern reached the European Cup final in 1974 but had required an equaliser in the final minute of extra time to secure a replay against an Atletico Madrid team heavily criticised for their tactics of intimidation. In the replay, though, two goals apiece from Uli Hoeness and Muller saw Udo Lattek's men to a deserved 4-0 victory.
Returning to the final a year later, Bayern had to soak up the pressure from Leeds United, and Peter Lorimer had a goal controversially disallowed for offside - prompting rioting among fans - before Franz Roth and Muller secured a 2-0 victory in the final 20 minutes. They matched Ajax's achievement in 1976, beating St Etienne 1-0 courtesy a Roth goal.
After Bill Shankly laid the foundations, Bob Paisley created perhaps the finest team English football has seen, winning the European Cup three times, in 1977, 1978 and 1981, as well as dominating their domestic league.
The '81 European triumph marked Paisley's tenth major trophy since succeeding Shankly in 1974 and he once famously remarked: "I've been here during the bad times, too - one year we came second."
Having beaten Borussia Monchengladbach and Club Brugge in '77 and '78, Liverpool beat Real Madrid 1-0 for their third success. With the likes of Kenny Dalglish and Graeme Souness struggling for fitness, the game was less than stirring - Ferenc Puskas said it was "not football" - but chairman John Smith said: "For us, winning is not just the most important thing - it's the only thing."
Paisley ended a 44-year spell at Anfield in 1983 and his successor, Joe Fagan, won the European Cup again in 1984 with many of the same players.
They returned to the final to face Juventus in 1985, but their 1-0 defeat was a mere backdrop to the tragic events of the Heysel disaster. English teams were to be banned from European competition for five years and the country's dominance of the European Cup was brought to an abrupt end.
AC Milan (1988-95)
After Silvio Berlusconi bought the club in 1986, Milan were transformed by coach Arrigo Sacchi and Dutch trio Marco van Basten, Frank Rijkaard and Ruud Gullit. Adopting a pressing 4-4-2 and moving away from catenaccio, Gli Immortali won their third and fourth European Cups, beating Steaua Bucharest 4-0 in the 1989 final and Benfica 1-0 in 1990.
With the departure of Sacchi in 1991, Fabio Capello arrived. If the team was less spectacular than his predecessor's, Capello's results were at least as impressive: Milan went 58 league games unbeaten between May 1991 and March 1993 and then reached the Champions League final three years in succession.
They won just one of those finals under Capello, against Barcelona in 1994, but it goes down as one of the most remarkable performances seen in the competition.
Free-scoring Barca had been favourites against a Milan side that owed much to the parsimony of its defence, and coach Johan Cruyff warned that the match could "determine the tactical direction of the game for the next few years".
Barca, though, went down to a 4-0 defeat, unable to find an answer to a Milan side featuring the likes of Paolo Maldini, Marcel Desailly and Zvonimir Boban, with Cruyff afterwards acknowledging Milan were "clearly the better team".