Guarantee- Something that gives a certainty of outcome
Interview- "You three kings came down here to win championships, not 1 championships-"
LeBron- "Not 2."
Interviewer- "LeBron, tell us about that."
LeBron- "Not 2, not 3, not 4, not 5, not 6, not 7."
LeBron- "And when I say that, I really believe that. I'm not just up here blowing smoke."
If that last line doesn't prove the certantiy of an outcome, then