As the meta for Smash 4 expands to include more and more tricky tech, it’s only natural that players would discover certain techniques that are very useful but only available to certain members of the cast. One such tech is Back Air (or Bair) Cancelling, which was recently documented by r/smashbros user MdFalcon. This tech can only be used by Mario, Dr. Mario, Luigi, and Peach, and it involves a player rolling towards a ledge, holding the direction so you go offstage and then inputting a back air as soon as your character falls off. If done correctly, the character should do an instant back air and then reset to their standing position with hardly any landing lag.
MdFalcon is not quite sure what causes this unique interaction, but suggests that these characters’ back airs shift their hurtboxes above the stage for a split second as you roll off, causing them to appear back on stage once the back air has finished. Out of the tournament legal stages, Back Air Cancelling can be performed on Duck Hunt, Town and City and Final Destination reliably. It can work on Lylat Cruise as well, but the stage tilting can mess up the cancel and just make you fall offstage.
So far, the usage of this tech is to set up for jab locks, with characters like Mario being able to back air to cause a hard knockdown, then follow up with a fireball to charged forward smash for a potential kill. It can also force situations where characters are forced to tech in order to avoid extra damage. Compared to other stage or character-specific techs, Back Air Cancelling seems very useful and like something which can be easily added into someone’s repertoire without having to change to a new control scheme or fundamentally change the way that they play.
Sources: r/smashbros, MdFalcon