Lots of excursions in this thread--all good.
I do agree with the notion that managers make a difference during games. Yes, of course players make the biggest difference, but managers during games adjust fielders locations (shifts), signal baserunners, hitters, and sometimes pitches, use pinch hitters, and of course control who pitches and when.
Where I part company with managerial critics is in the presumption that we know better than the managers. I did exactly that in game 1 when Kelly and Smith gave up 6 runs in the 8th, but upon reflection I decided Cora's decisions had a pretty good basis. Both are experienced relievers with a good array of pitches, but of course location is so critical every time a pitcher goes to the mound, and the manager can't be sure how that will hold up. Neither one that day had the right stuff, but even then it was a close call because we had two outs and a 4-2 lead before Denard tripled with the bases loaded. Kimbrel, our 8 figure closer, has pitched just two innings and gotten two saves. One was vintage Kimbrel and a dominant performance. The second was a tad precarious when he got the last out with the tying run on 2b and after he had given up a single and a walk.
I also find it fascinating that, with all the acclaim for now five straight terrific starts (30 innings, 3 runs), few have acknowledged that Cora in all five games had to manage his bullpen through an average of 3 innings per game and that overall that has gone well--except for the disastrous 8th in game 1. Games 2, 3, and 4 were all 1-run wins, which to me means you need a decent bullpen and a manager who knows how to use it. Something else no one but me has pointed out is that in the first four games Cora used all 13 position players in the starting lineup, 4 of his starters, and all 7 relievers.
In other words, to me the evidence to date is that Cora was a solid pick.