john;
There are no guarantees, only probabilities.
Yes, and
possibilities. The notions can be complementary or independently considered. It may be possible but not probable, it may be possible and probable and the other way around. The thinking opens previously blind paths to understanding an event. The discussion surrounding the Fukushima accident is one such event where the probability was considered "rare" that the generators would be flooded by a tsunami, but, despite a number of engineers calling for consideration of the "possibility" of flooding (and following through with an examination of the outcomes of that possibility), it was never done and within an hour or so, the pathway to the worst nuclear disaster in history was set at Fukushima.
Lee Clark, Possibilistic Thinking