There is no safe way to directly attack someone who has settled into a guard. No matter what line you choose, there is a simple and effective counter available. So you need to wait for your opponent to adjust feet, move his sword into another guard, take a step, prepare for a cut, basically anything that distracts his attention from the trap he has laid. This moment of distraction is called a “tempo”.
If your opponent won’t give you a tempo then you can create one using a provocation. The first provocation dall’Agocchie offers is a beat. With both fencers starting in Code Lunga Stretta, strike your opponent’s sword from your right using the false edge. Do this with a gathering step that pulls your left foot forward to meet the right.
The direction your opponent’s point goes seems to decide the next step. If the point goes to your left then,
turning your body well behind your right side, and turn a dritto tramazzone to his head in that tempo;
If your opponent perceives the beat and disengages under it, with or without the blades touching, then his point will be more to the right. In that case the second option seems to work better,
you can turn a riverso ridoppio to his right arm, followed by an imbroccata, and with it you’ll place yourself in porta di ferro.
Though they are harder to defend against than simple attacks, no provocation is without a counter. For both of these, a thrust to the face seems to be quite effective. Sink down into a lunge when you do this, stepping forward or back as the measure dictates.
A solid thrust will simultaneously catch the incoming cut on your strong or hilt. If you try to parry without the thrust your hilt will be too close to your body. This weakens the arm and necessitates an unusually wide parry, leaving you open to further complications.
If your point went to your left (the provoker’s right) then you also have the option to parry with a cut.
draw your right foot back a pace together with a riverso sgualimbro, with which you’ll go into coda lunga alta