Dedicated Scrum Master or Full-time Scrum Master?

Scenario 1 - She is a full-time scrum master for a team and gives all her time to the team, and attends all scrum events.

Scenario 2 - A dedicated scrum master for a team, not full-time, may work as a developer.

Arguments in favor of full-time Scrum Master

• If not full-time, what will happen to impediments to those needing immediate attention?
• She has to attend all events to ensure people practice the proper scrum.

The argument in support of not having a full-time Scrum Master

• But most of the time, impediments are not impediments but intra-team dependencies that the team has to manage, not scrum master.
• Scrum master is not needed in all events, and she has to only ensure those are getting done by the team.