I guess all I can say in response is that the point I made is the same regardless of what word is highlighted in bold. You are correct, the many different random & confounding & confusing aspects of life are what make it hard to say that Player X will hit Y #of home runs and steal Z bases. That level of uncertainty is why the projection models were developed in the first place. The computer runs a simulation thousands and thousands of times. Sometimes Bill Hall hits .380. Sometimes he misses 100 games after getting arrested for mopery (subsequently acquitted and returning for the tail end of the pennant chase). The projection that is published is the average of all of those thousands of simulations. Nobody is pretending that the projection is gospel (or they shouldn't be, at least). It's just a "best guess" - which is why I think it's weird that so many people get bent out of shape about them. My friends would be the first to tell you that I have a lot of theories about baseball that most stat-heads would consider inane - that hitting coaches do matter, that clubhouse morale does count for something, and that grit does have (marginal) value. I completely agree with you that a guy using a different grip, or a different arm slot, could make the projections look silly by comparison. But to completely dismiss the predictive qualities of data analysis really irks me.