Parries form the preparation for a successful riposte. As a result the selection of the parry makes a significant difference to the progress of a bout, the final score, and to your indicators, just like the preparation of any successful attack does. The same basic rules apply to the parry as preparation as does any attack preparation.
(1) Do not be predictable. If you parry every attack to 4th (3rd in sabre) with a lateral 4th parry, how long should it take an intelligent opponent to figure out how to exploit that pattern? Not very long …
(2) Choose the parry that allows you to attack an open line directly or open a closed line so that it can be attacked directly on indirectly. For example, if your opponent attacks in 6th, the odds are good that his recovery will be in 6th, keeping 6th closed. However, a change parry taking the blade to 4th opens up the inside line for a hit.
(3) Coordinate the preparation with the riposte to achieve the desired outcome. For example, if you parry 4th you can riposte by disengage into 6th (3rd in sabre). But if you use a change parry of 6th you can riposte directly into 4th (for two changes of line and two decision problems) or the change parry of 6th to draw a lateral response in 6th allowing an indirect riposte back into the original line of 4th (for three changes of line and three decision problems).
(4) Vary the distance. The advanced parry or a parry on an advance into the attack collapses the distance and reduces the opponent’s chance of making a successful parry. A parry in place allows a lateral parry and either direct or indirect riposte. A small retreat parry allows circular or multiple lateral parries and compound ripostes. An adjustable retreat causes the opponent to fall short (the parry by distance), allowing a choice of simple or compound parries.
(5) Vary the speed. Speed is less important than the ability to accelerate an action, allowing for a relatively slow parry with a rapidly accelerating riposte. Manage the speed and acceleration as needed for the distance.
(6) Use feints to control the opponent’s original attack. Feint parries encourage the opponent to complete a compound attack for which you are prepared. In the case of a feint of counterattack, the feint encourages the opponent to commit to their original attack in a line which is predictable and can be parried. The problem of parrying is made significantly simpler when the opponent’s attack is predictable.
So what is a practical catalog of actions in which you can use a parry to prepare the riposte?
(1) Lateral parry against a simple attack to prepare a direct riposte in the line of the attack.
(2) Lateral parry against a simple attack to prepare an indirect riposte to hit in the laterally opposite line by disengage or coupe, to the vertically opposite line by half disengage, or the diagonally opposite line by diagonal parry.
(3) Semi-circular parry against a simple attack to prepare a direct riposte in the line of the attack or an indirect riposte to the vertically opposite line.
(4) Circular parry against a disengage to riposte in the line in which the attack started.
(5) Change parry to riposte in a laterally opposite line from which the attack started.
(6) Circular parry to riposte indirectly into the lateral line opposite to the line from which the attack started.
(7) Change parry to riposte indirectly to return to the line of the original attack.
Case (1) represents a response that most opponents expect. Cases (2) through (5) require the opponent to rethink the problem based on either the different parry or the different riposte. Cases (6) and (7) force the opponent to rethink based on parry and then on the riposte.
The more times that you can force the opponent to rethink what they are doing, even if that rethinking is practiced and fast, the greater the possibility that the parry will successfully prepare the riposte. Everything from case (2) to case (7) is increasingly difficult to execute, and requires practice to ensure the correct timing of parry, riposte, and footwork (especially with the circular actions).