Bob Geren signed on to serve as the Mets' bench coach today, swapping places with Chip Hale, the former Met bench coach who recently joined the A's in the same position. A storm of Twitter snark obviously ensued. I've defended Geren plenty around here, but I've realized something about the criticism of coaching personnel, so I'm going to use Geren's departure from the organization as a jumping-off point.

First, how do we know he's a bad manager? Because the team didn't win? How do we know the team didn't win because of him? Can we identify concrete problems with his managing that led to losing? Were his lineups bad? Did his managing contribute to injuries? Did he play the wrong players in the wrong matchups? Did he manage the bullpen poorly?

I haven't seen anyone identify any objective reasons that Geren did poorly, which means we're left with behind-the-scenes components: was Geren an effective communicator? Did he have control of the clubhouse such that players were at their physical and mental best come game time? Did the players dislike playing for him so much that they weren't able to play up to expectations?

As to some of these, perhaps we actually do have some evidence -- Oakland certainly made a lot of poor defensive plays at the beginning of the year. (I would note, however, that the most ridiculous play most of us have ever seen, Brendan Ryan's infield triple, came in August, with Bob Melvin at the helm. Maybe this is because the proper tone was not set in spring training, but the "maybe" there just illustrates the difficulty of evaluating managing.)

The problem is that we end up relying on statements made by Brian Fuentes and Huston Street to evaluate whether Geren was an effective clubhouse leader. Neither pitcher has, to my mind, an incentive to lie or exaggerate, and each, in fact, has a significant disincentive to speak out at all (nobody likes a malcontent), so perhaps we're justified in crediting their statements against Geren. On the other hand, you know what they say about how many people have opinions, and in the end, we basically only heard from two people. Nobody else, of all the many players that Geren has managed, was laying the man out for the world to read.

Further, the lamemainstream media filter on issues like this is always suspect. Did the writers like Geren? Did they feel he respected them and gave them access and quotes to make their jobs easier? Or did they feel he was difficult to handle, an obstacle to be overcome? How might their feelings on Geren color our view of their decisions to print texts from Huston Street, to solicit quotes from Brian Fuentes?

Now, I'm not accusing Susan Slusser or Jane Lee of out-and-out conspiring to get Geren removed from his position. My point is that this small cadre of writers is the only way we know about anything going on off the field, and we know very little about the unconscious biases those writers might have. I'm not advocating disregarding what they write, but I don't know that we can take their stories at full face value. See also my piece about baseball reporting at The Platoon Advantage.

Add all this up and what do you get? The reason why voting for Manager of the Year is dumb, why criticizing or lauding the hiring of a manager or bench coach or pitching coach or hitting coach is impossible. We have no idea. (I'm as guilty of this as anybody. I'm sure you can read the archives of this site and find a hundred instances of me arguing for the hiring of Davey Johnson or the firing of Art Howe. Or, hell, defending Bob Geren. To the extent I have substantively argued that a particular coach or manager was, overall, doing a good or poor job, I repudiate such statements. I was wrong.)