Translation
This play completes the play of the scholar who came before me that left his dagger in its sheath and took your good one. How I do this has already been explained.
The counter to the ninth master is that when the scholar has taken the right hand with the dagger with his left hand, then immediately the player takes his dagger near the point and draws or pulls it towards himself so strongly that it directs the dagger to the elbow to make it change.
Interpretation
This is a curious picture to go with the text. The play of the 9th scholar is exactly the same as the 1st scholar. Fiore even tells us that he has already explained it before. He also then goes on to spend more time discussing the counter than the actual play.
Against a sottano stab, the master jams or deflects the attackers wrist with both hands. The different scholars then follow, generally by sliding the right hand to manipulate either the dagger tip or elbow.
To counter this as the player, leave your captured right wrist as a fixed point in space. Drop your hips down and drive your left hip forward. Use this movement to swing your left hand out and up in an arc.
Catching the dagger tip, direct it up and place it on the soft inner arm by the scholars elbow. Dropping your weight will also give you a little more freedom to bend your wrist up to do this. Exactly where it lands will depend on the length of the dagger and the details of the opponents grab, but it will be somewhere on the inside of the upper arm.
With the point in place, pull back with the right hip, driving the point in and putting an end to whatever play the scholar was planning. This will by no means finish the fight, but it puts you in control of the situation, as well as greatly reducing your opponents capacity to use their left arm.
Although the context is quite different, the mechanics of this counter are very similar to