Shortboost

Shortboost is a glitch that is used to start a speedboost in a shorter distance than is normally required. This is done by running 1-4 tiles while facing forward, and traveling backwards. Then, because of the trick samus starts to move forwards after an amount of time determined by how well the trick was done. This trick requires a few specific conditions to work:

• Must be at minimum 6.5 tiles away from a wall, door, or ledge and at maximum be 8.5 tiles away.
• The tile spacing required for a shortboost must be inside the same room, you can not start a shortboost with a door load mid back-flash.
• You need to have at least 15 tiles of space in order for the best shortboost to work. If you are going through a door transition after you have started your speedbooster this can cut down to about 14 tiles. Most useful applications of this trick are not used in an area with less than 16 tiles of space.

The inputs for shortboost are as follows:

• Start by holding the flash shift button and press the direction opposite of where samus is facing, this should be towards a wall, door, or ledge. This is the 'backflash' part of the trick.
• Mid-way through this Flash Shift you must input down and after doing so you must go neutral on the stick. Make sure you have released flash shift at this point otherwise you will flash shift forward and cancel the shortboost. This is the 'flash cancel' part of the trick.
• Hold Forward and press the speedbooster activation button. The forward input is dependent on how far away from whatever wall, door, or ledge you are. The farther away that you are the sooner you must hold forward and vice-versa.
• Once all of that is over the only thing left to do is store the spark

Trick uses

Screw Attack Shortboost or SASB for short is the most important application of this trick used in the optimal routes for any% and 100% NMG. Due to the circumstances surrounding the area you must do it in you will have other factors that add difficulty to doing the already difficult trick such as: Grapple door that can not be opened quickly, cold room with exponentially ramping damage, an underwater section with a blob that needs to be destroyed.

It is common to use a Map Buffer in order to ease the distance requirements of this trick. This would be done right before the edge of the water.

Here is a tutorial for SASB and shortboost in general by Arkandy:

You can use a shortboost in Cataris for an e-part near Kraid's lair to skip a speedbooster puzzle in 100% categories: