As with any high functioning organization roles need to be communicated and understood by the entire team. Otherwise chaos will destroy any chance of success. As to who does what, as the Head Coach you need to assign roles based on the strengths and weakness of your staff. As Head Coach you and you alone are responsible. You may decide to delegate authority to manage certain aspects of the game but responsibility cannot be delegated.
I have two AC's and each has specific duties on offense and defense. On defense I call the pitches, one AC handles the infield and the other the outfield. Pitch calling is what drives everything else on defense. One of the biggest mistakes I see teams make is calling pitches in a vacuum either by a coach or the catcher. It has to be a coordinated effort. Prior to each game I communicate my pitching strategy to the team as a whole. I tell them how I plan to pitch specific types of hitters so we are all on the same page. Then when we take the field we dynamically adjust the defense as needed. If things are going well I often turn over some or all of the pitch calling to the catcher. One thing that works fairly well is I call the pitch location and let the catcher choose the pitch. I have some pitchers and catchers that have been working together for 2 - 3 years and I have no reservations turning things over to them in certain situations.
On offense I stay off the field. I feel that it is critical to have regular communication with the pitcher and catcher and I can't compare notes from the last round of defense if I am headed to 3rd as they are coming in from the field. Also if I noticed a mechanical issue with the pitcher I can address it before the next round on defense. My HC runs the offense with help from the AC at the other base. We depart from the norm in that we communicate offensive strategy from the base closest to the dugout. That allows better communication from the dugout to the HC calling the offense, and it also makes doing showcases much easier. We use a combination of visual and verbal signals to communicate instructions to the offense. When a numbered play is called the entire team repeats it which keeps everyone engaged. I give my more seasoned players the flexibility to call plays on the fly. With an experienced runner at 3rd and home we just tell them to make something happen. They may flash some signs back and forth or just know what the other has in mind. More than once I have been taken back by their ingenuity and creativity when just given the chance.
I have two AC's and each has specific duties on offense and defense. On defense I call the pitches, one AC handles the infield and the other the outfield. Pitch calling is what drives everything else on defense. One of the biggest mistakes I see teams make is calling pitches in a vacuum either by a coach or the catcher. It has to be a coordinated effort. Prior to each game I communicate my pitching strategy to the team as a whole. I tell them how I plan to pitch specific types of hitters so we are all on the same page. Then when we take the field we dynamically adjust the defense as needed. If things are going well I often turn over some or all of the pitch calling to the catcher. One thing that works fairly well is I call the pitch location and let the catcher choose the pitch. I have some pitchers and catchers that have been working together for 2 - 3 years and I have no reservations turning things over to them in certain situations.
On offense I stay off the field. I feel that it is critical to have regular communication with the pitcher and catcher and I can't compare notes from the last round of defense if I am headed to 3rd as they are coming in from the field. Also if I noticed a mechanical issue with the pitcher I can address it before the next round on defense. My HC runs the offense with help from the AC at the other base. We depart from the norm in that we communicate offensive strategy from the base closest to the dugout. That allows better communication from the dugout to the HC calling the offense, and it also makes doing showcases much easier. We use a combination of visual and verbal signals to communicate instructions to the offense. When a numbered play is called the entire team repeats it which keeps everyone engaged. I give my more seasoned players the flexibility to call plays on the fly. With an experienced runner at 3rd and home we just tell them to make something happen. They may flash some signs back and forth or just know what the other has in mind. More than once I have been taken back by their ingenuity and creativity when just given the chance.