Examples of passive versus aggressive goaltending in one on one situations with your defender trailing.
Passive
http://video.nhl.com/videocenter/consol ... ent=PHI553
Aggressive
http://video.nhl.com/videocenter/consol ... vent=MIN35
http://video.nhl.com/videocenter/consol ... vent=MIN22
I prefer the aggressive approach, which should take away time and space, while forcing the shooter to react sooner or be jammed.