This season we have seen Barcelona lose to even the weakest teams. So if Real Betis plays well, they have a chance to win. And you say that, Real Betis have a chance to score 12 points in the next 3 matches, if they can play well. However, Real Betis are in such a weak form now that it is difficult for them to win against Valencia and Granada. However, the players will be confident if they can win against Barcelona.
I know Real Batis performed quite well during this season, but I don't see the chance for them to beat Barcelona. Barcelona must have a bigger motivation to finish at 2nd place, they won't let Real Betis to get even 1 point. Although Barcelona was defeated several times against weak teams, but in the next remaining matches, they must already be evaluated for their previous mistakes. Especially, their current coach is Xavi Hernandez, he won't miss any points again.