Sorry, don't have access to Roth's book at the moment... What exactly is the "it" that is "perfectly safe 99% of the time", that he is referring to?
While I have nothing but the utmost respect for Hal and Margaret Roth, and will freely admit my own experience offshore fades to virtual nonexistence in comparison to his, if he is suggesting that sailing a small yacht in the western North Atlantic - particularly between Newport and Bermuda, in November - is perfectly safe 99% of the time, well... I would have to respectfully disagree, and side instead with Don Street's, or John Harries' take on the matter...
But, I'm gonna guess that's probably not really what he's asserting, particularly in regards to the sort of passage you cited, and that the crew of George Day's LIME-N' was waiting to undertake... :-)
I think we can both probably agree that it's fruitless to attempt to assign any precise percentages to something like this, no? And, that Roth likely tossed out his 99% figure simply for effect? Given the limitless variables that might apply relative to various types of boats, differing levels of experience of crews, variations in seasonal weather patterns from one year to the next, and so on, ad infinitum?
You hit it on the head with the bolded part. Your take on what I was saying about the 99%/1% ratio and how it relates here was as wrong as your notion that my saying the Knowles relying on the Weather Dude's okay to leave on their trip (the same thing you and Ausp were making fun of newbs for doing) brought forth the "obvious" conclusion that "one can never, EVER know for sure whether it's safe to leave the dock, or not."
I don't really know how you come up with these crazy comparisons and extreme conclusions, I just like watching them spin out all over the place. That's all.
To be very clear, Roth was talking about the overall chance one has of actually running into a very serious storm while out cruising. In his 40 years, 200+K miles, 3 roundings of Cape Horn etc. there were a very small handful of times the conditions rose above F8 (Gale). This worked out to maybe 1% or less of his cruising time spent in "a strong gale or a storm".
So the point is if you're at all smart and watch what you're doing, your chances of avoiding a boat-breaking storm are very, very good. As I said, I like those odds.
On the other hand, if you rely on others to do the thinking for you, don't rely on established standards of safety and preparedness, or misjudge conditions because of herd mentality...that ratio may drop to your 95%...for newbs and experienced sailors alike.
Even so, your odds are still pretty good to leave the dock. Just be careful where you're going - and have your boat prepared...maybe even to some degree of ISAF standards.