The optimum portfolio depends on the various expectations of choices available and the degree of variance in performance which is tolerable. The greater the number of selections, the less will be the average year-to-year variation in actual versus expected results. Also, the lower will be the expected results, assuming different choices have different expectations of performance.
If you can predict the rate at which you create (or create and grow) qualified pipeline, and you know your average close rate(s), then you can start predicting your revenue.
While the individual man is an insoluble puzzle, in the aggregate he becomes a mathematical certainty. You can, for example, never foretell what any one man will be up to, but you can say with precision what an average number will be up to. Individuals vary, but percentages remain constant. So says the statistician.
Perhaps the efforts of the true poets, founders, religions, literatures, all ages, have been, and ever will be, our time and times to come, essentially the same - to bring people back from their present strayings and sickly abstractions, to the costless, average, divine, original concrete.
I am not more gifted than anybody else. I am just more curious than the average person and I will not give up a problem until I have found the proper solution.