Another nice insight, Doc. :)
It is an interesting one for me because there seems to be a strong correlation in the data between fast center fielders and how deep they play (the same correlation applies to corner outfielders). We remember well that Andruw Jones and Jim Edmonds traditionally played VERY shallow and traditionally put up good defensive numbers.
So between those observations, it may be that if you have a GREAT defender...play him shallow...if you have a less than great one...play him deep...and if he's even average and tries to play shallow...he will lose.

Why did the Mariners play shallow this year and deeper last year? I think the reason is that the fences were more shallow. Teams instinctively play PROPORTIONALLY to the wall...but XBH are the same depth in all parks. Outfielders should play the spots where the line drives and fly balls will land...not the spot that is proportionally the same between the wall and the infield arc.

An intrepid sabermetrician who's willing to do more than look at general correlations and devise metrics that find situational advantages to be gained by a more informed data-driven approach to in-game management could save his team a bunch of runs without taking anything away from the guys whose job it is to find talent in the first place (the scouts).
Working in baseball, even in my lowly capacity as a scrub code-monkey, does tend to make one aware of how many situational advantages teams are NOT leveraging. This may be one such situation. And the Mariners may be one of the worst teams in baseball at leveraging situations to their advantage. For example, I'm not certain of this, but I believe that the Mariners are playing the extreme three-infielder-one-side shifts far less often than other clubs...and there is significance evidence that the extreme shifts are saving teams a bunch of hits (league-wide BABIP is PLUMMETING in direct relation to the increase in defensive shifting).
I don't think the baseball-dumb criticisms that USSM frequently levies against the GM are a result of bad-GM'ing or bad talent evaluation...but rather bad situational leveraging. Think for a second...how many times did we see a Mariner hit a 100 mph screaming meme RIGHT AT the second baseman who was in the perfect spot to flag it down up the middle or directly into the glove of the first baseman who was playing near the line? Now how many times did we see a Mariner PITCHER benefit from the same kind of excellent positioning? I think those numbers will not be the same...they may not even be all that close.

I cannot comment at all on what type of environment the Yankees posses for analysis work. I think my learning isn't so much an increase in game-related knowledge as it is an increase in exposure to types of analysis that I hadn't considered on my own. The benefit of working in what amounts to a think tank like environment is that you have people around you THINKING. :) Differently than you think. I also think that getting a chance to talk to people who've been in the game a while gives me a sense of perspective on the usefulness of sabermetrics to date vs. what teams really want to be able to do. All of this is valuable whether or not I can continue in the game (I would like to...but I am also trying to start a family and I need to make enough of a living for that to fly).

If the coaching staff isn't positioning the outfielders properly, thus improperly utilizing the strengths and weaknesses of the talent the GM is handing them, why wouldn't the GM fire the staff? Seems like a smart thing to do. Lenny Wilkens fired Bob Hopkins when he couldn't take advantage of all the talent he gave him. At the time, I think everyone kind of assumed there simply wasn't enough talent there to win. Only Lenny truly understood the talent he assembled, and furthermore knew how to realize its potential.
I don't know how a manager can influence a lot of things a ball player does, but positioning the team wisely is certainly one of them. Strange that finding a coaching staff like that should be called scapegoating. As you reminded us of Bill James's research, Doc, teams that get turned around usually do so with a new manager.

Right there.

There's times to go for them and risk giving up longer yards and times to play it safe and keep them as short as possible. A back looking to intercept seems very relatable to a shallow CF yet one is well known the other just discovered by the public stat community.

....but don't break.
I've always distrusted the non-Willie Mays CF'ers who played a deep 2B. Now there is some actual number type data that supports that.
When folks are critical of an OF'ers "routes," what they are really poking at is their instincts. The shallower you play, the more demand on your instincts AND your speed. Playing deeper reduces the demand on both.
Two balls hit in front of the CF equals a runner in scoring position, probably 2B. It only takes one ball over the CF to create that situation...or perhaps worse (if you're the defensive team).
This can not be coincidental....it can't be that EVERY outfield position for the M's is costing them lots of bases unless there is some organization effort to play shallow. If so, it amounts to some decision-maker missing a bunch of evidence.
moe

"...since about 1998 that the Mariners are:
(A) out-scouted
(B) out-data'ed
(C) out sign-stole
(D) out-everything'ed"
Seriously, we rally for our cause, debate, cajole, excoriate, argue, plead, etc., etc., etc., when the real problem is an entire organization that is inept when it comes to baseball, and, in my opinion, underachieving even when it comes to business. What difference do minor improvements make in such an environment? It's like taking the now-deceased longtime White House correspondent Helen Thomas and trying to make her eyeliner look better.

have Ken Griffey Jr. (in his prime), Randy Johnson (in his early prime), Edgar Martinez (in his prime), Alex Rodriguez (in earliest years but achieving as if in his prime), and Jay Buhner (in his prime), a perfect, serendipitous storm of talent, and never even make it to the World Series?
having lost that window of opportunity, got another serendipity with Ichiro, only to employ him in a way that wasted his talent.
If perhaps there are other organizations that could waste such opportunities, the list is extremely short.