This play is easily understood and you can well see that I pull him to the ground. And when I have him on the ground, I will want to drag him after me. And when the long tail no longer pulls him along, then I will injure him.
Fiore tells us that this play is easily understood, and on a conceptual level, this is true. You throw a weighted chain around your opponent legs and pull. Even if you only catch one leg, it will be enough to sweep your opponent off their feet. You can then rush in to finish them off, probably using a secondary weapon.
Having said that, this play poses a lot more questions than it answers. The weapon is so strange that it doesn’t even have a name. Its nearest equivalent would probably be the Japanese kusari-fudo, although the similarity is only superficial. Fiores version seems remarkably unwieldy.
A close look at the masters weapon shows that the chain extends along the handle, through a collar at the head of the handle, then on to a length of rope which holds the weighted head. The chain down the handle and through the collar suggests that the weight is retractable.
The players weapon appears to be the same weapon with the weight retracted back to fit against the handle. If this was the case, you would expect to see them holding loops of chain in their left hand, which they very clearly are not.
A weight on the end of a chain like this is a ferociously difficult thing to control. Without a lot of training in its use, that style of weapon is often more dangerous for the person wielding it than anyone else. The idea may have been to use it for one good swing, and then drop it for a more conventional weapon, regardless of whether you hit or missed. Without any real context, it is difficult to know.
It could potentially have been intended to capture an opponent for ransom rather than rather than fighting with them in the typical sense. Given that the whole book is structured around fighting duels using knightly virtues, this is an unusual intended outcome that doesn’t seem to fit the model. It is such a strange weapon, that not much can confidently be said about it, other than it is not a weird as the weapon used by the 3rd master of pollaxe.