His first 25 games in charge of Sunderland = 27 points. If he does exactly the same we'd get 39. Use his overall points per game from Sunderland and it works out as 41 points.
His 21 games at Palace = 26 points. Would have us on 38 with 4 games left so that's better. Use his points per game from CP it works out as 43 points.
His record, and I include WHU also, is patchy. You can say that's due to having crap teams to manage and that's true but he's hardly the god like guarantor of survival some portray him to be. Going on his past record it's likely we'll stay up but it'll be close.
The thing is people have fallen hook line and sinker for his "never been relegated" claptrap. All the above says to me is he has been very lucky. Constantly finishing in the low 40s and relying on 3 worse teams in the league. Not that he's some specialist.
It's the same sort of revisionism that clouds Everton in the 90's. That we were somehow specialists in miraculous survivals. It's not true, we got really lucky, and if you got offer me the decade that followed I'd take it every day, over a team that thrived when it was on the brink.
One final point in this, is Sunderland went down like a shot last season, and Palace look like they are going to do similar. He inherited (Palace certainly) in 15th and at no point ever looked to move beyond just staying up. Finishing below 11th is a major blip for us, but if Allardyce repeats his patterns it won't be.
There is no magic potion in the human form of a fat headed brummie named Sam that can guarantee you survival. I understand why that's reassuring for people. If I could sign a form that said survival now I'd do it. Allardyce, in spite of his protestations doesn't give you that though. What he gives you, is you will be in the frame for a great number of works, and you better hope lady luck shines on you.