Well, since here is a specific target, I won't have to cover everything. The trick is making it easy to visualize - tangible, not ethereal and fuzzy like so much of mathematics can be to the faint of heart.

Not easy in a text only medium, but what I've got so far works.

Just finishing up with the traditional coin toss analysis.

Next is to tackle non 50/50 odds. And then, to skew the curve off center.

Brian