of the top of my head a model would have to involve some type of scale that was able to account for the difficulty of pass attempted, the other options available (opportunity cost), the level of pressure the passer was under, where on the pitch the passer was, where on the pitch the pass went, how far the ball traveled, controlability of the pass, the danger creation of the pass. Then rate all of these on scales from -10 to +10. Then figure out a way to weight each category apropriately to come up with an overall rating for each individual pass, then this stat could be used in many ways both in average score per pass and total score created through passes
Like I said it would take a long
