If Rafa does not win RG outright, he is guaranteed to be thrown out of top 8.
This is independent of how deep he goes there and how other players perform.
If you want details, read on:
1. Novak is way ahead of everyone that even if he loses in the first round he will be way ahead of
everyone, including Rafa, after RG.
2. If Rafa does not win RG outright, he will lose at least 800 points (2000 for winning last
year - 1200 best case scenario of runner up this year).
3. As last year's final was between Rafa and Novak, all other players can lose a maximum
of 720 points only (SF points are 720). So, those who are currently ahead of Rafa will
contine to be ahead of Rafa (even if they lose in the first round) as long as Rafa does not win RG.
4. Ferrer, the current #8, has only 360 points (quarterfinal) to defend. Even if he loses
in the first round, he will move ahead of Rafa, in case Rafa cannot win RG as Rafa leads
him by just 80 points.
5. Stan, the current #9, lost in the 1st round of RG last year. Hence, he has nothing
to defend. So, even if he loses in the first round, he will move ahead of Rafa as long
as Rafa does not win RG since Rafa leads him by only 725 points now.
6. With the six players ahead of Rafa, continuing to remain ahead and Ferrer and Stan
surpassing, Rafa will drop down to at least 9 if he does not win RG outright.