Sometimes it's easy to figure we've got everything figured. But we don't. Not everything. And sometimes it's good to circle around and hit a problem from a different direction. Case in point: Tangotiger takes another run at figuring out how many runs a great fielder saves:

So, using WOWY (With Or Without You) based on balls in play, I selected the best twenty or so infielders (2B, SS, 3B) since 1993. It's mostly the names you know: Everett, Sanchez, Bartlett, Rolen, Reese, Hudson, Inge, etc. By looking at a large enough number of great infielders, the idea is that all the noise around them will cancel out. My only additional constraint was that he must have been on the field for at least 1000 outs for a given team-season, and must have been off the field for at least 1000 outs for that same team-season. I came up with 68 such seasons since 1993. The total number of games played was 5386 games on the field and 5400 games off the field. You have to admit that that's alot of games. When the star fielders were on the field, their team allowed 4.60 runs per game, and when they weren't on the field, they allowed 4.83 runs per game. Per 162 games, this difference comes out to 37 runs. --snip-- If I take the top 20 fielders in UZR, minimum 162 games, their average is +18 runs per 162G. So, we should feel quite confident that a great fielder adds some 20-ish or so more runs than an average fielder, per 162 games. I know most readers here see the range for fielding as +/- 20 runs. That's pretty much spot on.

I snipped the section where Tango repeated the exercise with outfielders and first basemen, and came up with progressive lower numbers (19 runs for outfielders, 15 for first basemen). But without running through the math, I'll vouch for the +/- 20 runs as a solid guideline. Which is huge. As you know, for every 10 runs you pick up one win. So the difference between an elite fielder and a lousy fielder is four wins. Granted, it's exceptionally rare for a fielder to make that much difference. We're talking about 40 runs per 162 games, but most guys don't play 162 games. We're also talking about the difference between the best and the worst, but teams rarely are faced with such a choice. When the Yankees do (finally) move Captain Jetes off shortstop, they're probably not going to replace him with Adam Everett (or his analog). And of course we can't consider defense in a vacuum; players have to hit, too. But the point is one we've been making for quite some time, and especially since the defensive metrics have become more and more reliable: Everything counts. And even today, there are great players whose greatness is generally missed because too many pundits are not aware of those +20 runs.