How come Barcelona won against Chelsea in UEFA Champions League?

Answer 1

The away goals rule is a method of breaking ties in association football and other sports when teams play each other twice, once at each team's home ground. By the away goals rule, the team that has scored more goals "away from home" will win if scores are otherwise tied. This is sometimes expressed by saying that away goals (or at least one of them) "count double" in the event of a tie.

The away-goals rule is most often invoked in two-legged fixtures, where the initial result is determined by the aggregate score - i.e. the scores of both games are added together. In many competitions, the away goals rule is the first tie-breaker for such cases, with a penalty shootout as the second tie-breaker if each team has scored the same number of away goals. Rules vary as to whether the away goals rule applies at the end of normal time of the second leg, after extra time, or both. The away goals rule is intended to encourage the away team to be more aggressive. In football, at least, it often leads to a nervous first leg; the home team is unwilling to commit large numbers of players in attack lest they concede a goal, whilst the away team attempts to defend and snatch an away goal to aid them in the second leg. Such tactics arguably make the second leg more exciting, after a low-scoring first leg leaves both sides with a chance to win. There is some debate over whether the away goals rule creates an unfair advantage in playing away first, followed by at home - with the other team squandering their home advantage in the first leg due to away goal fears - and this may be a factor in its somewhat patchy adoption for competitions. Anecdotal evidence certainly suggests that most teams feel an away goal puts them in the driving seat

Answer 2

Barcelona can win the champion League in 2009.

Answer 3

they have good players and because they have very good trainers.