The goaltender

By moving out from the goal line towards the shooter, a goaltender covers a larger proportion of the net from the shooter's point of view. Coming out too far, though, leaves the goaltender unable to get back across for a pass to the other side of the ice.

This is the central trade of the position: depth against lateral coverage. Almost every goaltending decision — how far out to challenge, when to retreat to the post — is a version of it.

The butterfly is a stance in which the goaltender drops to the knees with the pads splayed outwards, covering the bottom of the net across its full width. It exists because the lower part of the net is where most shots go and because a puck along the ice cannot be caught reliably.

The trade is that a goaltender down in the butterfly has committed, and the upper corners are more exposed. Which is why shooters are taught to elevate the puck against a goaltender who drops early.

The crease protects them: contact initiated by an attacking player with a goaltender in their crease disallows any goal scored on the play, and the attacking player is penalised. Outside the crease, only incidental contact is permitted, and then only when the goaltender is playing the puck and the attacker made a reasonable effort to avoid them.

On an icing, a goaltender who feigns or attempts to play the puck waves off the call. And for most penalties assessed against a goaltender, a team-mate serves the time in the box — the goaltender stays on the ice.