Left-foot braking is a pretty difficult skill to master and as
such shouldn't be practiced on public roads. If you get it wrong
it could easily end up causing a crash. Part of the difficulty
of left-foot braking can be attributed to the fact that the left
foot is not as attuned to pedal sensitivity as the right foot.
Due to the fact left-foot braking is generally only required during
competition driving it is best left to the track.
Left-foot braking involves altering the balance of a car during
cornering by applying the brakes during cornering while still
keeping the accelerator depressed.
A situation which could require left-foot braking is when the
driver is cornering under power. If the driver doesn't want to
lift off the throttle then left-foot braking can induce a mild
oversteer situation, and help the car turn-in better. Mild left-foot
braking can also help reduce understeer by moving the balance
of the car further over the front wheels giving them better traction.
Left-foot braking is very hard on a car, especially the brakes