Yeah, basically what born2pizza said. There have been stories of some people winning without a key, but I don't know how much truth there is to them.
But you are basically in the right too that checks and challenges determine who wins as well, but I seriously believe that only the final challenge counting is total BS. There have been games I've played in which the person sucked at the final challenge as well as checks and keys, but placed higher than at least one person who should have beaten them easily.
I think every challenge counts towards who wins, not just the last one. I think that was where one of my own wins back in the day came from.
Only time I won without a key is when no one in the top 5 had a key honestly.
Otherwise I strongly believe you can't win without one.
33% checks 33% keys 33% comps. Icarus_Mark I think every challenge counts as well I agree with everything you said!