Thanks for the thoughtful reply. I get your point, and do think making less errors is very important, and I was to stress that errors and error rate is factored into metrics.
I'm not sure if you were saying "effort" has something to do with range differentials, and I guess it might in some cases, but range is part physical attribute, instincts (getting good jumps, positioning correctly and knowing by watching the pitch location, where the batter is likely to hit the ball to you: as in to his left or right and maybe leaning that way) and skill.
You really don't think getting to 140 more balls but making 5, 10 or even 20 more errors is not worth it?
I don't understand the "days of Jeter not wanting to make an error? or that those "days are over." Jeter didn't get to many balls hit his way, because he couldn't, not because he chose not to, just as some SSs, today cannot get to many balls others do get to and finish the play. You mention changing conditions, but aren't some errors given based on easier plays vs tougher ones? In both cases, we expect the conditions even out, just as we do for BA, OBP, SLG, ERA and other traditional data. Also, when we see certain players have the same data, year after year, even when changing teams, parks and other factors, I think it's safe to say the numbers are just as accurate as flg % and BA (which also depends on the assignment of an error or not, to a small degree, and the luck or unluck of conditions, such as parks, opposing pitchers and defenses,,,,)
On this, "All the hypothetical what-if components of metrics render them useless for evaluating players. " 1. You do know the assignment of errors or no errors is subjective, right? Also, it's not hypothetical to see and prove that some SSs make way more plays than others. They know how hard a ball is hit and how far away from the defender it is. They can then see who gets to it and who doesn't. That part is not guessing or hypothetical. The formulation of things like WAR do factor in the likelihood that a play made or not made affects the chances of a run being scored, but what makes you think that is any more faulty than the scorekeeper calling some obvious errors a hit and vice versa?
You say most fans don't know the formula, and you are right, but do you? If not, how can you be so hypercritical of something you don't understand. If you heard a simple explanation on how they compile the data, you may see it's not so hokus-pocus as you think. Maybe not.
Simply put, not all great range defenders are "flashy," and even if some are, if they make 140 more plays that the steady Jeter types, while also making 10-20 more errors, some because they are throwing off balance after making a spectacular stop, it's a joke to say the steady Jeter type is better. It's not even close.
Stopping 140 base hits in exchange for making 10-20 errors, that would have been hits, anyway with the Jeter types is no comparisons, at all. Even if all 20 "extra errors" led to the runner getting to 2B on a bad throw, it is still a clear advantage having a great-ranged SS over a statue who never makes errors.
Forget the metrics and hypothetical aspects of some of these metrics, range is a tangible and observable aspect of the game. We can all see with our naked eyes that some short stops have amazing range, while others have way less than average range. The differentials between the best and the worst are easily 80 a year, or one play every two games, while the differential between a 5 error SS and a 25 error SS is one error every 8 games. Keep it simple, and it still shows that errors are not the only major aspect of defense. IMO, it's not even #1, let alone something that blows range away in value.
I played next to a great range SS and saw that value, firsthand. He took so many hits away from the other team, that if you counted those hits and added them to his offensive numbers, he's have hit over .450 and maybe even .500.