His ground game is on the decline especially his BH/movement, from 2008.
It will come down to his Serve if he can pick-up cheap points on serve, if he can't he will have to slave-away against mugs to get the W. So he might win 0,even the french is not guaranteed.
If his Serve is Great he can challenge all 4.
Serve is good 2/4 is my guess.
Even if that's true, it doesn't matter. Why? Because the rest of the players have been declining even worse. And there are no serious young players on the rise.
I agree his backhand is worse than in 2008, but forehand and serve are both vastly superior.