A downshift technique where you blip the throttle with the side of your right foot while maintaining brake pressure with the ball of that foot. This matches engine RPM to wheel speed during downshifts for smoother corner entry.
Bentley's Speed Secrets provides the step-by-step: "1. Begin braking, using the ball of your right foot on the brake pedal while keeping a small portion of the right side of your foot covering the gas pedal but not pushing it yet. 2. Depress the clutch pedal with your left foot, while maintaining braking. 3. Move the shift lever into the next-lower gear, while maintaining braking. 4. While still braking and with the clutch depressed, roll or pivot the right side of your foot onto the gas pedal to blip the engine." In Ultimate Speed Secrets he emphasizes the key principle: "The reason for downshifting is not to slow the car. That's what brakes are for. Too many drivers try to use engine compression braking to slow the car. All they really achieve is upsetting the balance of the car." His Speed Secret: "Brake first, then downshift."