Backflip
A backflip is a type of jump that can be executed quickly and gains a decent amount of height. A backflip is performed by jumping while crouching in a stationary position (if the crouch and jump inputs are entered while moving, Mario will perform a long jump instead).
Properties
Backflips have a height of 496 units[1], thus making them identical in height to both sideflips and vaults. Backflips have a fixed height, meaning this figure is not affected by how long the jump button is held during the jump. During a backflip, Mario will also move backward slightly, making them useful in situations where Mario needs to clear an overhang or gain distance away from a wall during his jump. Backflips do not have a fixed horizontal distance, meaning if the player holds backwards or forwards it will affect how much horizontal distance is gained by the backflip.
Because sideflips also move Mario laterally a similar amount, backflips and sideflips are often interchangeable in certain scenarios. However, backflips are generally more suited to situations where Mario must initiate a jump from a standstill, while sideflips are better suited to when Mario is previously moving.