The vulnerable points when close enough that the foibles cross are the wrist and forearm. The guard would have to be bypassed of course but this remains an action that is little more than presentation of the blade.Wyes said:From guard with the foibles meeting we certainly couldn't land a blow by an extension of the arm, largely because the guard (that I am familiar with, rather than something like Capo Ferro, but I know the Spanish had a similar guard to the Italians) already has the arm mostly extended.
The lunge is responsible for the extended range as the maximum range of an single action attack without adding any stress is effectively a full lunge step, plus the length of the arm, plus the length of the weapon. This allows a fencer to close a surprising amount of distance with a single action without even considering any of a number of techniques that involve any forward motion before beginning a lunge. The action you described, sounds like some form of displacement. Moving the rear foot inward and to the back necessarily rotates the torso effectively closing the outside line by maneuver. This does have the effect of gaining some distance though, for the average fencer, this is a matter of an inch or two. It does, however, ensure that any follow on lunge is much longer ranged (often a foot or more) but this would comprise two separate fencing actions most of the time.Wyes said:Any further extension of the arm only nets you a few extra inches, and the blade length is typically 36-40". The extension of the arm was necessary to start the attack, but it certainly doesn't reach the opponent - the lunge was necessary (or that step where the back foot moves out sidewards, the name of which I cannot remember - I just remembered it being kinda cool footwork).
The nature of the weapon in question and the dramatic reduction of viable fencing actions, by my estimation, makes it a requirement. That the lack of such an implement requires either baiting an attack or fully committing to your own attack is a fairly silly set of requirements when one's life is on the line.Wyes said:Being preferable doesn't make it necessary, which is more or less the argument you're making here. If both duelists have only a single weapon, then there's no advantage.
A transition to defense not only involves halting the offensive action but it also, by necessity, requires responding in kind. The flaw of the rapier is the difficulty inherent in transitioning lines - a flaw so absolute that even the footwork reflected the problem resulting in a circular style all but eliminated once the weapon was shortened. That difficulty of transition might not seem like much but given how little time one can have to defend against a thrust, the loss of a fraction of a second is easily fatal.Wyes said:If one duelist does have an off hand weapon, then yes, you are at a distinct disadvantage. It is not difficult to transition to a defence with the rapier upon withdrawing from an attack, but you do lose offensive options once the thrust is spent.
To put it simply, when the addition of a secondary implement vastly increases viable offensive and defensive options, I'd call it "necessary". This isn't to say that secondary implement needed to be a blade or shield - even wrapping your off hand with a heavy cloak would allow for a parry!