They can't keep up a defensive standard against Madrid. That hasn't happened in the past 3 years thus, it'd be a big luxury In the phase of an unevenly structured team schedule; betis is one of sort though. Thanks to Madrid that they've utilized properly -- a rear opportunity and that has kept 'em going smoothly.
Real Madrid is a good team and so is Barcelona. I believe both teams have the capability of winning in the La Liga El Clasico. But both teams also have problems as well. We are talking about the defense of Barcelona being very chaotic.
But at the same time, it is Real Madrid who has not been performing well defensively this season. I think that is the only reason people might actually give Barcelona some chance of winning. However, the Barcelona attack will have to be coordinated. Otherwise, they will not be able to win against Real Madrid. Real Madrid also will try to do their best to win this match because they know that this match is very important for both teams to decide which team will have the advantage over the other in the long run.
I am also a little surprised to see Antonio Rudiger not performing well with Real Madrid. He is generally a very good defender who can also act as an emergency attacker.