It is nice that you know that in the game of football anything can happen. It is true that Real Madrid has been consistent and doing well in their previous champions league games in the past years. Real Madrid are favorite the win the Champions league with experience a good squad but if you say Borussia Dortmund Dortmund are going to be playing the biggest match of their career I will disagree with you in 2013 Dortmund played against Bayern Munich despite lossing to Bayern Munich so Dortmund has played a big match in the past year.
Am backing Borussia Dortmund to win the UEFA champions league trophy.
Can we compare current Real madrid and Bayern Munich strength? I believe that even Borussia Dortmund's players will admit that playing against Real madrid is definitely going to be different playing against teams like Bayern Munich currently. I know they have played lots of difficult matches in the past but saying that playing against Real madrid is the biggest match of their career is not entirely wrong statement too. I'm not referring to playing in champions league final as the biggest or great match but I am talking about the team they are playing as the biggest thing in their career considering that it's UCL final again.
Both teams are strong for eliminating series of teams to reach this very stage of the competition and they are both prepared. We can not confidently predict the outcome of the match despite that it is obvious to tell which team is stronger and which is weaker. Football is a game of luck and the strength of the team doesn't always translate to winning the match but it will be surprising to everyone who is familiar with these two teams if Real madrid lose the match. Let deal with the situation on ground and do away with emotions.