So when messing with wireless command blocks I ran into the issue. For this I provided some pictures and I've triple checked my sources so all of this should work:

Command block A (Copy and Paste'd):

scoreboard players set @a tff 1

This block isn't the problem, its just here to show I know this should work.

Command block B is where the problem seams to start, I believe it has to do with there being 2 arguments (Copy and Paste'd):

testfor @a[score_ttf=1,score_ttf_min=1]

Command block C is where this gets confusing. This is diproving my theory of multiple arguments(Copy and Paste'd):

testfor @a[score_ttf=1]

I did power these A B C order