Article from BP by CJ Nitkowski. Good read. And for the record, it isn't a saber bashing article but it could seem that way from the intro I pasted below. I just didn't want to paste too much article and get grounded.
One thing that has always bewildered me about the sabermetric community, more specifically its members in the media, has been its general discounting of the value of coaching, especially at the major-league level.
I have read more times than I care to recount how little impact a manager can have on wins and losses, but that’s another topic for another day. What really befuddles me, though, is when a sabermetric scribe plays down the value coaches can have at the big-league level, with doubt about their usefulness dripping from every sarcastic word.
What I find most puzzling is that not only is it not true, but it comes from a source that could never understand what makes a good coach in professional baseball without guessing. Those opinions on MLB coaches are about as valid as mine on ballet instructors.