Well at least I figured they haven't won very often. So I thought I would use google and hunt down their performance. Here is the list since 1980.
1980- W, W Loss in playoffs
1981- W
1982 -
1983- L
1984- L
1985- L
1986-
1987- L
1988- W
1989- L,L
1990-
1991- W
1992- W,L
1993-
1994-
1995- L
1996- L
1997-
1998- L
1999- L
2000- W
2001- L,L
2002-
2003-
That makes them 7 and 14. So it has been pretty difficult for them to win on the West coast. Consider the travel involved and the change of venue, I don't think this is too surprising. And a close look at the years, shows they didn't do that great when they had great teams and a great QB. So the Bills will be very lucky to split the Seattle and SF games. If they win both they deserve Kudo's, because they haven't done that since 1980.