He died a few days later. One of the players who originally resented Rickey's integration of Robinson into the game later came to recognize the importance. Managers and GMs alike could learn from Branch Rickey even today. Managers are a combination psychiatrist, brother, sergeant, pastor, judge and father. They also need to understand the game.
Managers have to know their players as individuals.
They can't handle them all the same. There are some things you cannot control as a manager. You can't control their basic ability. You can encourage them in all of these areas and you can offer drills and advice for their improvement. None of us are the same.