If you are in a position to delegate a responsibility to a responsible person, then you have something to trouble your mind during your leisure hours. You need to think, think and think to decide on a choice. Before putting a person in a higher position, where he/she has to manage a handful of his/her fellow team mates, you need to consider a lot of factors which might, if not considered, make you worry for your decision.
Let us say, you have a person in your team who is a good team player and who had already conquered your heart for the leadership position, about which we are talking about. The most important factor you need to consider is the impact of his promotion, on the team, which he is going to manage. He may be your favorite. But, what if he is not for the team? What if someone in the team already had a bad experience with him because of his behavior? What if he bullies? What if he is a person, who shows favoritism towards his personal friends in team, which could spoil the productivity of the team? What if he is a person, who always make fun of others and one way or other had hurt others' sentiments? He may be good at his office work but, when it comes to handling people, the decision of choosing him for a leadership position should be people-centric rather than work-centric, since work is, of course done by people themselves, say his people who are going report to him.
A good leader should be like a judge. He should neither bias nor bully. He should be equanimous and should demonstrate maturity and be a role model for his fellow beings. He should be very careful in humorous situations, as there are chances where any statement made for fun, could hurt the receiver deeply. In a team each member will be different in age, race, and sex and will have difference in thoughts and opinion. A good leader is a person who considers all these and makes sure that each one in the team feels comfortable and happy for being in the team.