Man, this is a tough one. I'm in the same position. My opponent is up 2 pts on me right now and is starting Tynes tonight which should get him 10-13 pts (I'm expecting a good game for him). So I need to go w/ upside on this one. Jacobs has disappointed me all year with 7, 8, and 10 pt games. He rarely gets into the end zone now that they're utilizing Bradshaw on the GL more. I've always been told to use the players in the big games that got me there... well unfortunately Jacobs didn't get me where I'm at so he's riding pine. Ganther is still unproven but they're saying he's the man in WAS and he also looked good catching passes out of the backfield so in PPR he gets a small bump.
This what really makes up my mind though... I like putting in players that are highly motivated and need to prove themselves to keep their job. Ganther fits that role nicely and he has a great head on his shoulders. While he won't run all over the Giants, he should still net 60-70 rush yds, 20-30 pass yds, and a TD. The Giants have given up 17 TD's to RB's this year! I'll take my chances and hope for the best! Oh yeah, and Jacobs runs upright and gets hurt often... don't be surprised if he comes out and sits half the game for tweaking a knee.
2010 12-team .5PPR
QB - Ryan, Vick
RB - S. Greene, Forte, Stewart, F. Jones, Sproles
WR - Moss, Megatron, NYG Smith, Floyd, M. Williams (TB)
TE - Cooley
D - CIN (week to week)
K - Bironas