Roles and craft
Captain
The on-field leader: calls the toss, sets the field, changes the bowling, decides declarations and reviews, and carries the result.
The captain is the player who leads the side on the field, taking the tactical decisions that a coach cannot make from the dressing room.
Cricket gives its captain more real-time power than most team sports. The captain calls at the toss, sets every fielding position, decides who bowls and from which end, picks the moment to take the new ball, chooses when to declare, whether to enforce a follow-on, and whether to spend a review. Between deliveries the captain is also the side's manager of moods, geeing up a flagging bowler or calming a batter who is charging every ball.
Because so much rides on the role, captaincy is part of selection. A great player who cannot read a game, or a fine tactician whose own form suffers under the burden, is a real problem. Many teams now appoint different captains in different formats, and most captains lean on the senior bowler and the wicketkeeper for a second opinion on the field.
In Masterstroke: you make the on-field calls yourself, ball by ball, but you still name a captain for each format, and the board has an opinion about him.