If you have Arbiter in a multiplayer game you can seperate the enemy forces by just using Statis field on your or enemy units.Here you must be carefull that optimum seperation must be done.So the enemy force is divided and you can destroy them easily.Statis field is very usefull against Terran especially.You can use statis field ability for delaying enemy build up at a strategical zone.This ability gives you enough time to deploy your forces around the freezed enemy units.