Big Boy Room
|Seaweed Room||Adjacent rooms||Dust Torizo Room|
In all categories, the player should move left as quickly as possible in order to start the Metroid cutscene as soon as possible. For categories with Space Jump this will mean retaining jump speed through the door transition, then Space Jumping until the camera locks. For all other categories, the optimal strategy is to shoot the dust enemies, then mockball on the ground between the first and second pillars sticking out of the ground.
By doing careful jumps manipulating the Baby Metroid's position, you can exit the room without the Metroid draining your health, followed by the cutscene where you're temporarily locked in place.
A very basic explanation of the Space Jump variant's beginning is pictured below.
Metroid Skip Skip
For runners who can't get the Metroid Skip, they would be faster damaging themselves as much as possible on the side hopper, before jumping straight into the Metroid's grasp. The side hopper damage can be sped up by pseudo screwing into it, since a pseudo screw resets the invulnerability period. This is done especially in 14% categories, since runners lack both Wave Beam and High Jump Boots, making the Baby Skip much more difficult and time-consuming.
If you fail the Baby Skip (or succeed at the Skip Skip), you should face right before you reach 1hp and get locked in the crouch position. When facing left, Samus goes through the animation of standing back up slowly. Facing right skips this animation and saves 35 frames.
If you go through the door transition while the Baby Metroid has a hold of you (including if it grabs you during the fadeout), you will be in a permanently slowed down state in terms of your horizontal velocity. You can complete the game like this, but the escape sequence will be significantly more difficult.
To remove the slowdown, you'll need to get to the save station, save, then reset your console.
If you reach 1 hp during the door transition, there's a decent chance you will be softlocked in the crouching position.