"Madrid never won la liga after being in some fixture to 7 points of Barça."
La Liga is more competitive nowadays. So a 7 point gap is not unsurpassable. When Messi's form takes a dip at some point in the season, Barca will inevitably drop some points and that's where Madrid need to capitalize. But right now, they should just try to stay in the race by not losing any more games. One more loss and it will be 10 points which suddenly looks scary.