Maximum points achievable are currently as follows:
Us - 77
Spurs - 76
Villa - 72
Liverpool - 70
Now obviously us, Spurs and Villa can't all get maximum points as we have to play those two. I can't see Spurs getting anything at the Swamp so that means they can only get 73, even if they beat us, Arsenal & Chelsea.
So the ideal scenario for us is
1) Liverpool don't beat Chelsea;
2) Spurs lose at OT;
3) Spurs don't win both of their games against Arsenal & Chelsea;
4) We beat Spurs & Villa.
So in that case Liverpool could get no more than 68, Spurs no more than 68 and Villa no more than 69. We've got 65 in that scenario with 4 games to play so need two wins or a win and two draws from the other 4 games (Brum, rags, Arsenal & West Ham).