Here's a look at the remaining schedules for our closest pursuers.
Sevilla (48 pts): Home (4): Real Sociedad, Betis, Deportivo, Granada
Away (4): Valencia, Sporting, Espanyol, Athletic Club
Hard to imagine anything other than four more home wins, isn't it? As for the road matches, those could hold the key. If Sevilla can't manage to win one of them, then they'd end up with 64 points at best.
Celta Vigo (48 pts): Home (4): Depor, Betis, Granada, Malaga
Away (4): Sporting, Espanyol, Athletic Club, Atleti
These guys are still not out of it, and on paper they have four very winnable home ties, some winnable away ones too. But for them to get to fourth, they probably have to win at least six of their remaining matches if Sevilla keep winning at home. My guess is they will get something like 15-17 more points at most, so 63-65.
Athletic Club (47 pts): Home (5): Granada, Rayo, Atleti, Celta, Sevilla
Away (3): Malaga, Levante, Las Palmas
Maybe what....12 points from the home matches? The three remaining away ones are all winnable, but at least three of those teams will be fighting for points. I'm figuring 6 points from the three, which might be optimistic the way Las Palmas have been playing of late. That would give them 65 points. Keep in mind Villarreal would win a tiebreak with them.
Villarreal (54 pts): Home (3) : Getafe, Real Sociedad, Deportivo
All very winnable, but we can't switch off. The point versus Barcelona was great, but now the key is for us to WIN the other three home matches.
Away (5): Eibar, Real Madrid, Valencia, Rayo, Sporting
So the way it works out between Sevilla and Villarreal is this: Villarreal need to match Sevilla's home record, which means Sevilla would pick up three points if they win the extra home match.
Villarreal needs to match what Sevilla does playing Sporting and Valencia on the road.
Then it comes down to Sevilla's away matches against Espanyol and Athletic Club, compared to our away matches against Eibar, Rayo, and Real Madrid. Even if Sevilla win those two (keep in mind they haven't won away all season), a draw, a win, and a loss in those three Villarreal aways would still leave us a point ahead.
Given that it looks as if the other teams could end up on 65 points, three home wins, four away points would give Villarreal 67, which would be enough.