Fredi is fairly rigid in setting bullpen roles. He is not the only manager who is like that. But it is not a good thing imo. Among other things, it leads to excessive use of certain relievers over short periods.
The current roles that Fredi has laid out calls for the big 3 to be used when the Braves are tied or ahead by 3 runs or less (sometimes 4 runs or less) in the last three innings. Walden gets the 7th, Carpenter the 8th, Kimbrel the 9th. Sometimes Avilan is brought in to help out in the seventh.
The other relievers are used when the team is behind or in innings before the seventh. Or in extra innings.
There are some other issues with Fredi's pen management. One has to do with not properly taking into account splits. He treats guys like Avilan and Thomas like LOOGY's when in fact they are not bad against righties. And he tends to leave guys like Schlosser (and Gearrin in the past) in against lefties in high leverage situations when he shouldn't. Having Schlosser face Duda, Young and Murphy in the eighth inning in a one-run game is an example of what I'm talking about.
He also tends to favor and disfavor certain pitchers in ways that do not fully reflect the relative qualities of the players in question. But I think every manager does that.
Finally, he also has a tendency to overuse guys who are doing well and not keep guys who are struggling active enough to give them a chance to work out of their problems. I'm talking about pitchers here. I'm hoping he doesn't lose confidence in Walden and put him in the deep freezer. Walden is one of those guys you have to be careful in using. Use him too much and he breaks down. Use him too little and he loses his edge. He's the kind of pitcher that can have problems with a manager like Fredi.