Capoferro: Plate 8
This plate established the classic problem of geometry posed by the attack to the leg. Against it, slip the leg and strike to the head or arm. Instead of cutting the leg, cut the head! But beware the counterattack into the cut shown on Capoferro: Plate 10...
You will find the same basic idea of taking advantage of the geometry of the cut to the leg versus cut to the head in the 7th play of the Second Master of the Fiore's Plays of the Zogho Largo, in I.33 (Update with wiki link) and indeed in many other systems.
Figures that Demonstrate How Much Measure is Lost by Attacking the Legs
The sword of the figure C being gained by the figure D, this same figure C turns a riverso to the leg of the figure marked as D. D is able to strike him during the turning of the riverso, with a stramazzone to the arm or a thrust to the face, as a consequence of his leaning too far forward; as the figure shows, the said figure D moreover draws his right leg back during the attack. Always, I say, that when D was stringering the sword of C, had C been a shrewd person, he would have given a riverso to the face followed by a mandritto fendente to the head and thus he would have been safer.
Current Training Video
Legacy Wiki Video
Related Resources:
Blog post on the geometry of the cut to the leg, with Fiore's play as the example: The Fiore Translation Project #19: Slip the Leg, and Kick the Nuts
Books: The Duellist's Companion.
Workbooks: The Complete Rapier Workbook
Online courses: [1].