The way I see it, obviously there are only two outcomes
1. If Pakistan win, Yasir will have to come good with a 5 fer or more. And windies will be all out within 40-50 overs tomorrow.
2. If Windies win, Samuels and Bravo will see them through tomorrow, Samuels will surely score a century.
For me, knowing Pakistan, it's going to be 60 - 40 West Indies, especially because the Windies batsmen, Bravo in particular will be going out with a special plan against Shah. They will try to attack him and break his concentration.