Let's imagine that at given time (a) a thing is not possible, and that at given time (b) it may become possible, although given time (b) is not a thing that can be clearly defined from the viewpoint of time (a).
Let's also imagine that both (a) and (b) are dependent on variables (c) and (d).
Variables (c) and (d) are each in possession of independent rationale. That rationale may be weighed upon by further variables—for (c) q, r, and s, and for (d) x, y, and z.
I've never been very good with exponents or percentages.
But I distinctly hear probability say, "Guts, girl! Just take the wave."
Then under his breath he mutters, "Don't be surprised when you're stuffed in the barrel."
Good thing I like the ocean.