Possibly the most difficult distance problem comes with the family of counterattacks - the stop cut (sabre) or stop thrust (foil, sabre, and epee) and the time hit (a stop thrust or cut with opposition). The problem lies in the reality that the two actions have different objectives with varying operational constraints in all three weapons.
When we say operational constraints we mean the conditions under which the hit has to be made. These depend on:
(1) the rules of priority applicable to the weapon - in foil and sabre right of way applies, and the counterattack must either be in the opponent's preparation (an attack in preparation is a counterattack) or the opponent must make a significant error in the mechanics of the attack for right of way to be gained. The requirement of the rules that the counterattack must land before the initiation of the final action is effectively obsolete in a world where the advance-lunge delivered from a marching step is a one tempo action. In epee the counterattack is much freer, as all it has to do is land in an 80 millisecond window, depending on the tactical objective of the fencer (more about this later).
(2) the target - foil has the most difficult target for the counterattack. To reach the foil target the counterattacking fencer must commit deeply and hit while fully exposed to a hit on the torso by an opponent. Sabre offers the advanced target, and the ability of the sabre to either cut or thrust makes actions to the opponent's arm relatively easy to complete. The epee target, although much larger, is effectively restricted to the opponent's arm, unless unusual circumstances open up other areas. With both weapons with advanced targets, the arm becomes the focus for most counterattacking action as it offers the best chance of landing first.
(3) timing -
... lockout time in foil is so slow that a counterattack that lands against an attack that is going to land is guaranteed to result in two lights. With a competent referee this is a loosing proposition. With a referee who only watches the lights, a very fast counterattack, especially by a fencer with longer reach, may result in the counterattack landing first, with the first light, and being awarded the hit. It is poor theoretical fencing, and risky, but part of fencing is fencing the referee ...
... sabre is a different proposition. The 110-130 millisecond lockout time means that your goal is not to avoid being hit, but rather to avoid being hit before lockout time shuts the attacker's action off electronically. This means that an attack to the forward target that lands while allowing the fencer to avoid the incoming attack by a well timed retreat or jump backward has a good chance of success.
... epee is the most complex, while seeming the simplest. After all, lockout time in epee is 1/25 of a second, or 40 milliseconds. You have to land more than 40 milliseconds before the attacker to win the touch with a single light. But that view misses a whole range of tactical uses.
Rules, target, and timing mean that distance has a different impact in each of the weapons:
(1) in foil the fencer has to hit the torso. To avoid two lights the fencer either has to have a longer weapon arm or be able to hit and accelerate backwards against a slower opponent.
(2) in sabre the fencer wants to hit the advanced target. To avoid two lights the fencer relies on the quick retreat or jump back with a cut or thrust to the oncoming arm.
(3) the picture changes in epee because the epee fencer has a choice of objectives. If the objective is to hit and avoid a double hit, the traditional reassemble or the retreat or backwards jump works with the thrust to the forward target. As long as the objective is to avoid being hit, the fencer wishes to land 40 milliseconds in front of the attacker. However, the epee fencer has several tactical situations in which a double hit may be desirable.
... in general, in pools a double hit when ahead is not desirable because it impacts the fencer's indicators.
... in situations where the fencer is behind and has a realistic hope of changing the flow of the bout and winning, double hits are to be avoided as a deliberate tactic - all they do is preserve the opponent's lead. A deliberate double hit at 3-4 is particularly undesirable.
... but if you are going to lose, double hits maximize your scoring opportunities and help your indicators, and if a particular attack cannot be answered with a parry, a double hit early in a bout may also preserve the current relationship of the scores.
... in the direct elimination, this changes, and the double hit becomes a viable tactic if you are ahead. Because indicators have no influence on direct elimination results, the fencer who is ahead preserves that lead by stop hits resulting in two lights. If the score is tied at the end of regular time and the fencers are fencing for a decisive single touch, double hits by the fencer with priority increase the pressure on the opponent and can force errors that allow a final single hit.
How does the epee fencer achieve a double hit on the stop? Working in the fencer's favor is the 40 millisecond lockout time, but it is important to understand the timing. If A attacks B and lands 41 milliseconds ahead of B's stop hit, there is one light. If B's stop can lands within 40 milliseconds after A's attack there are two lights. But what if B lands ahead of A - effectively B has 80 milliseconds to work with, 40 in front of the attack and 40 behind. This means that it may be to B's advantage to rapidly close the distance on A's attack with a lunge into the attack, rather than the traditional retreat. This maximizes the chances of hitting within the 40 before and 40 after window.
The time hit problem is different. A time hit works by intercepting the opponent's attack and forcing it away from target with opposition - in effect combining an active parry with a stop hit. In reality this is restricted to the response to a simple attack or interception of the feint of a compound attack in a slowly developing attack. Properly executed the time hit is clearly an attack into the attack. Now the action is delivered by a simultaneous extension into the attack or the simultaneous extension with a lunge. The action must start as soon as the opponent's attack starts with explosive acceleration. This works in all three weapons, including in sabre with both cut and thrust (most effectively in 3rd) - because there is one light right of way is not a factor. Because both fencers are closing, distance is not a problem (unless the opponent attacks from close enough that a response is not possible). It requires a nice sense of timing with very quick response (considering the closure speed of both moving forward), the ability to identify where an attack is going to be delivered (with an understanding of the opponent's tactical choices), and plenty of practice.