Luigi (SSB)/Back throw
Luigi grabs the opponent by the legs, swings them multiple times, and then throws them back. It is one of the weakest back throws in the game, only dealing 12% and having below average knockback for a back throw. It cannot KO Mario at the center of Dream Land until he is at 153% and at 110% when used at the ledge. The throw is rather slow, although it has a collateral hitbox while Luigi is swinging his opponent, which deals 10% to bystanders. This hitbox is not particularly powerful although it does grant Luigi some protection while performing the throw. Overall, Luigi's back throw is one of the least effective back throws in the game although it is still a solid option to set up edgeguards and to score KOes in some situations. Luigi is usually better off using his forward throw, although if he is at the ledge, facing away from it, back throw would still be his preferred option.
In the Japanese version, Luigi's back throw was identical to Mario's back throw, dealing 16% and much higher knockback. This naturally made Luigi's back throw much more useful, although the power from his original back throw has been transferred into his forward throw to compensate.
Throw and Hitbox Data