Boost grabbing is a technique in which the momentum from a character's dash attack is transferred into a dash grab, resulting in a longer-ranged dash grab. Discovered in Super Smash Bros. Melee and retained in every game since, the boost grab is a very quick and useful form of dash attack canceling, as it cancels the dash attack for a much faster grab, leading to lowered lag. As some characters also make their dash attack sounds while performing a boost grab, boost grabbing can also act as a mindgame.
Performing a boost grab
The technique is made possible by exploiting the window for making a grab input using attack + shield. To perform the boost grab, the player must first dash and then press the attack button while dashing to perform a dash attack while pressing the grab button immediately within the first few frames of the dash attack, with the exact window varying between games. If done correctly, the dash attack will be cancelled and the player will instead perform a dash grab.
Some characters make sound effects when they perform a dash attack, such as Fox, Luigi, and Snake. As a result, some players recommend learning boost grabbing with these characters, as to learn the precise timing of a boost grab.
The boost grab is easier to perform in Melee and can be performed by any character. However, the player cannot jump cancel the boost grab and only Sheik, Fox, Falco, and Marth benefit from it; Sheik notably benefits from boost grabbing, as it almost triples her grab range.
All characters in Brawl can perform boost grabbing. Snake, however, drives the most use out of it, as it not only grants significant distance, but it can assist him with tech chasing with his down throw and can allow him to more easily regrab characters out of grab releases.
The boost grab makes a return in Super Smash Bros. 4, but in a weaker state. It works with all characters, but the grab range benefit it gives is minuscule. However, Rosalina & Luma are notable for benefiting the most from this technique: while running, inputting a dash attack and instantly grabbing can make Rosalina perform her dash grab, while Luma still performs the dash attack. This makes the grab safer, and also means they can potentially deal 3% upon landing the grab.