But, the first is 12 points ahead as far as I know, even with a win on the extra game would be 9 points. I am not sure if Real would even lose 9 points until the league ends but even if they do, that would mean Barcelona can't even lose once during that time. Not sure if they can do that, the league is all but over right now and anyone who wagered on Madrid outrights should be already paid by the looks of it.
As for Barcelona, they still have 10 matches left and tomorrow will play against Sevilla and at the end of the season will play against Villarreal. With his good form now at least Barcelona have no problem to win the match but anyway, if Barcelona expect to win the title at least Real Madrid have to drop points in at least 4-5 matches. For me, this is very unlikely even though anything can still happen, because so far Real Madrid have only lost three games. Therefore, in the remaining 9 matches, I believe Real Madrid will not lose many points, they have a high winning mentality which is certainly able to maintain their position.
It is really hard for Barcelona to win each and every match in La Liga because they also have to concentrate on the Europa League.
But, if Barcelona keeps playing the way they are playing right now I think they will be able to finish in the top two easily.
On the other hand, the position of Real Madrid is obviously going to be safe because they are not going to lose consistently. at least not at that level where Barcelona can give them a challenge for the league title this season.