2/08/2009 found through Meriam-Webster

quantal: relating to, or having only two experimental alternatives

Daryl’s career, and quite possibly his survival, was quantal of him perfectly landing a fifty-foot jump over a shark tank full of rabid badgers on a specially modified, nitro-powered unicycle; the fact that he had agreed to do it while carrying a basket of poisonous snakes lead some to believe that this would probably be his last stunt either way.