Deflections are used to stop an opponent action, but they must be done properly.
Any action that deflects an opponent's action from hitting you is a deflection, or displacement and they come in two general flavors:
- Empty displacements
This is what happens anytime you stop an opponent's cut without threatening them at the same time.
These are usually done as a 'parry then repost' form of fencing. The main issue with this style is the gap between the deflection and attack, creating an opening for the opponent to deflect your blade, or perform a single time counter and steal the initiative from you.
- Single time counters
Ideally a single time counter is done as an attack that intercepts the opponent's blade on your weak as you drive your own weak to their body.
These are arguably the defining aspect of the German school of swordsmanship and the majority of actions in the Fechtbucher focus on this type of counter.
Displacements are done as counter actions
This means that they are always done in response to an opponent's action. In other words they have acted first and taken the initiative, which you will now need to take back from them.
Alternatively to using displacements you can work to take the initiative from the Zufecthen, the opening of the fight, and maintain control over it through distance, and attacking with good form.
Against a bad opponent this will provoke them into using empty displacements, creating openings for you to attack, i.e. a Nachreisen, Abschneiden, Schnappen, etc.
In other words if you seize the initiative, there are several options for defeating empty displacements.