It started with the foot movement. Vasari was able to notice the change in footwork for different actions that Reifer did.
When defending, Reifer's feet were wide apart, making himself stable and rigid.
When thrusting, his left leg slid back while his right leg bent forward, providing extra reach and getting low to make himself harder to hit.
When slashing, Reifer would alternate between stepping forward with his left leg or right leg. When steeping forward with his right leg, he would slash from 2oclock to 7oclock. When stepping forward with his left leg, he slashed from 9oclock to 3oclock.
Every so often Reifer would mix it up. His stance wide and low, with one leg stretched out to aid his spin. His upper body twists to gain momentum as he spins his sabre rapidly overhead with both hands. It looked weird but was oddly effective since Vasari had the hardest time defending against that attack.
