While timing in sales, as in most everything, is, as they say, everything, it's very difficult to optimize for this (in an enterprise sale, hurricane forecasting, stock market).. The variables (and processes) that a team can most impact, are 1) The product itself, and 2) The relationship with customers and clients. Of course, each informs (and enhances) the other, but teams would do well to optimize for these two variables (easier said than done) -- good timing may end up being the byproduct of a great solution positioned well to key decision-makers who know and trust and love what you're building.