Well there is a right Vom Tag, and a middle one... so there has to be a left Vom Tag as well, hasn't there? We make all master cuts cut from both sides, so it is simple logic, right?
Looking through the manuscripts and manuals of the 15th and 16th century, it is obvious that the guard Vom Tag can be done in numerous variations, as described in this article: How do you do the Vom Tag? However, one vital question has received fairly little attention; the question if there really is a proper left Vom Tag for right-handed fencers described in the fechtbuchen.
The closest thing I have found in my research is in Paulus Hector Mair's "Arte Athletica" from 1542, where he uses a guard that looks like a reversed Schlüssel, as seen on the left. It is a position you can easily come into after striking from right Vom Tag into Alber and finally continuing up into this particular stance. However, upon closer examination it appears as if this stance is held with the long edge resting on the upper arm and shoulder, ready to strike an unterhau with the long edge or an oberhau with the short. Perhaps it could be considered a form of Vom Tag, but then the Schlüssel should also be considered a form of Ochs...
Apart from this stance, I have found no descriptions of a left Vom Tag for right-handed fencers, which is slightly confusing since it seems to be common to practice, especially with beginners.
Why then is there no left Vom Tag?
Well, the answer is fairly simple. If you are right-handed, Liechtenauer and his followers tell us to strike first from our strong side. What follows then is either a direct hit or a bind. Here you have a few choices; you can thrust, wind and thrust, cut with a duplieren (a second cut while remaining in the bind), or if your opponent presses on, do a Zucken (withdraw and strike) or a Schnappen (snap around and strike). All these techniques start from the bind with outstretched arms in langenort/sprechfenster and this is from where your nachschlag (counter-strike) or nachstoss(counter-thrust) comes. There is no need to move back into a left Vom Tag before attacking from the left.
Furthermore, as most of us probably have noticed, holding the sword in left Vom Tag is simply uncomfortable, especially if you try to keep some form of edge aligned towards the opponent. You are forced to either keep the wrist at an awkward angle, or to rotate the grip in your leading hand. The left Vom Tag feels "unnatural" and perhaps this is another part of the explanation why it appears not to be a part of the KdF as we know it. Just about everything else, and especially the primary and secondary guards come very natural.
Following this line of thinking, it is only logical that you do have right and left versions of the guards Ochs, Pflug and Alber, since these are the "ending points" into which you can cut or parry from Vom Tag. And basically these are retracted versions of the four Hengen, apart from Alber.
None of the reasoning above does in any way imply that you shouldn't ever cut from the left. Only that the guard system is somewhat assymetric. This is also the case if you look at, for instance, Joachim Meyer's guards and stances for polearms.
So, shouldn't we practice it anyways...
...since it might come in handy as a last resort parry? Well, that depends. Nothing in fencing is ever wrong as long as your head stays in one piece. But, the Ochs, the Pflug, the Schrankhut and the Schielhau fill this need already. So, there really isn't much need for a left Vom Tag.
Of course you can practice it and even find a use for it, especially if you use the type of circular strikes that are common in the "late" manuals of Paulus Hector Mair and Joachim Meyer, but keep in mind that these were written partly with school fencing in mind, and as a result the thrusting and related winding techniques are less focused upon, if at all, since they were commonly forbidden to use. This naturally means that working from the bind is less relevant, compared to the fencing of earlier masters.
To sum it up; it appears as if the left Vom Tag is not within the scope of the earlier "Liechtenauer tradition" intended for "life and death" fencing. In fact Master Sigmund Ringeck even advises against striking the Vorschlag from the left, since you will be weak in a bind. Yes, it works sometimes in sparring, but would you be willing to bet your life on it with a sharp? That is the perspective from which Ringeck writes:
If you are a right-handed fencer and you are closing to an opponent and you think you can hit him, do not strike the first blow from your left side because you are weak there and you cannot resist if he binds strongly against your blade. Because of this, strike from the right side, you can work strongly on the sword and you can use all techniques you like.
Finally, I would like to encourage anyone who knows of a reference to a proper left Vom Tag in any of the manuscripts and manuals regarding the longsword to please contact me. I would love to have to revise this article with evidence of a left Vom Tag for right handed fencers.
Feb 8 2011 - It is interesting to compare Paulus Hector Mair's "reversed schlüssel" above to the guards of Fransesco Alfieri, of which two basically corresponds to the Liechtenauer Vom Tag/Zornhut and Ochs and the other two with Joachim Meyer's Schlüssel and Paulus Hector Mair's guard reversed schlüssel seen above. An Italian influence on especially Meyer has been discussed in depth for a long time and this seems to further reinfore that idea. However, there are obvious differences. Alfieri's fencer changes the leading hand and even reverses it sometimes...
A still not properly substantiated idea I will explore eventually, is the idea that a large portion of the techniques described by fencing masters like Joachim Meyer and Paulus Hector Mair are in fact designed for use against multiple opponents and when fighting outnumbered. This thesis relates to the article on "Spinning around" that is also available in the article section.
Sources: (These will be updated properly shortly)