To my knowledge there are no definitive illustrations of Nebenhut (side/close guard) for the longsword. Here is what we do have:
When you fight with one, and are oncoming to him, thus stay with the left foot forward and hold the sword with the point to the earth, at your right side, so that the long edge stays up, that goes for both sides.
The relevance of this image is disputed because it seems to be reused several times. It is also a good match for Meyer’s description and illustration of Schrankhut.
Joachim Meyer 1570
In this guard, position yourself thus: stand with your left foot forward, hold your sword by your right side, with the point toward the ground, so that the pommel stands upwards, and the short edge toward you.
From the Close Guard you will fence into the Crooked Strike; as you have been struck to an opening when you hold yourself in the right Close Guard, then step springing with your right foot to his left well away from his strike, and strike with crossed hands above and behind his blade to his head, twitch nimbly (where you don’t want to wrench out to your left) above him with crossed hands and hit strongly with the outward flat from below to his left ear; however where he won’t strike, then fence such as you will learn from the Middle Guard following this.
My inspiration is Meyer’s phrase “fence into the Crooked Strike”. If we look at Mair’s Crooked Strike stance, it does seem to fit the description.
Paulus Hector Mair
The Krumphaw from Both Sides
When you come to the closing with the opponent, set the left foot forward and hold your sword with the point at your right side and remain hence standing in the Krumphaw (Crooked/Off-line strike). If he then strikes you from above to an opening, step outward with your right foot and give him a Krump to his right side and strike him at the nearest opening.
If he gives you a Krump like this and you stand with your right foot forward likewise in the Krumphaw, then step in with your left leg and displace his strike with your long edge. Then immediately follow outward with the right foot and drop a Krump onto his sword with your short edge and with that cut through his head.
The play I need to apply this to is this…
Joachim Meyer 1560
If one fights against you in the Guard of the Roof, thus you come in Zufechten into the Side Guard, you must above all not wait in that long, then when he bears witness to the strike and as soon as he brings his sword into the air, thus lay on against him with a Thwart strike, instantly as it clashes, thus cut quickly again around with the long Thwart, to the other side of his sword, that is now attacking, if he strikes around, thus you cut after, if he displaces, then deceive him with the weak, so that you cut him in the after.
Since the purpose of this guard is to throw a Zwerch, we should take a look at how Meyer defines it.
Joachim Meyer 1570
For the Thwart, conduct yourself thus: in the Onset, position yourself in the Wrath Guard on the right (concerning which see the previous chapter), that is, set your left foot forward, and hold your sword on your right shoulder, as if you intended to deliver a Wrath Cut. If your opponent cuts at you from the Day or High, then cut at the same time as him with the short edge across from below against his cut; hold your quillons up over your head, as a parrying for your head, and at the same time as the cut, step well to his left side. Thus you parry and hit simultaneously, as shown by the two figures on the left in Image H.
As you have done this Thwart on the left, so you shall also do it on the right, except that you shall hit with the long edge against his right.
As expected, it is really easy to throw crooked strikes from this position, but when I first tried it the zwerch seemed to be impossible to use.
Lets start with the left. I discovered that I turn the quillons so that they lock into the crux of my arm. This feels really comfortable, but severely limits what I can do from the position. Keeping it free allows me to perform the long edge zwerch with ease.
On the right side the quillon lock-up is an issue, though not as bad. A far more interesting discussion is how to throw a zwerch from the right. Meyer says that it should be thrown “across from below”, which is certainly possible. But if my sword is low as seen in Paurñfeyndt’s illustration it seems as though I’m pushing the edge rather that looping it like we in other Zwerchs. Also, my left arm keeps getting hit. Also my hilt ends up too low.
Looking again to Mair’s illustration, I tried it with the pommel held high, actually above my head. Using a push-pull mechanism with my hand, this allowed me to actually swing my sword in the right path for a rising zwerch. It comes in fast and clean with a nice “whoosh” noise and my hands end high. I haven’t used it as a parry yet, but it looks like my hands and arm will be well protected.
It also comes in with the long edge. Or rather, my right hand rotates around the blade so that the thumb is on top, effectively swapping the short and long edges.
To correct this I need to use Nebenhut as a transitional guard. By that I mean I cut through the guard but never pause in it. Doing so allows me to generate power without shifting my grip.
And thus I’ve arrived at my working interpretation. More news once I’ve had a chance to do some field research.