The Scrum Guide has significantly changed the definition of the SM role more than seven times. These were huge changes - not small adjustments.

The Scrum Guide has described the SM as a "servant leader", and gone on to explain that. But the explanation was wrong. A servant leader is not what is described by Scrum.

If you read Greenleaf's original paper defining servant leadership, a servant leader is a _leader_. He says clearly that a servant leader leads, and a servant leader's followers follow.

According to Greenleaf, what makes a servant leader such is that,

1. The leader demonstrates that they put the interests of the team above their own; and,

2. The leader acquires the trust of the team: the team believes that the leader makes good decisions.

This is at extreme variance with how Scrum describes a servant leader.

I suggest reading James Hunter's book "The Servant" for a better description of servant leadership.

Also, teams need more than servant leadership. They also need transformational leadership, and other kinds as well.