Rules Analysis
Marking Violations:
Double-team: If a defensive player other than the marker is within three meters of any pivot of the thrower without also being within three meters of and guarding (II.G) another offensive player, it is a double team. However, merely running across this area is not a double team .
"Merely running" means running for the exclusive purpose of reaching the other side. Running with an ulterior motive of interfering with the thrower in any way is not "merely running" and is a double team.
Disc-space: If a line between any two points on the marker touches the thrower or is less than one disc diameter away from the torso or pivot of the thrower, it is a disc space violation. However, if this situation is caused solely by movement of the thrower, it is not a violation.
Vision blocking: If the marker deliberately blocks the thrower's vision, it is a vision blocking violation.
Only the thrower may call a marking violation, and to do so must call out the name of the specific marking violation.
When a marking violation is called, play does not stop. The violation must be corrected before the marker can resume the stall count with the number last uttered before the call minus one (e.g. stalling one...two.. fast count ..one...two...). If the marker resumes the stall count before correcting a marking violation, it is another instance of the original marking violation, which may be called by the thrower.
When a marking violation is called, the marker should immediately stop counting. The marker should then correct the violation and resume the count at the appropriate number.
If a marker commits a marking violation after being called for a marking violation during the same stall count (XIV.A.1) but before the thrower is in the act of throwing, the thrower may choose to either call another marking violation or to treat the marking violation as a general defensive violation (XVI). To treat it as a general violation, the thrower must call violation.