Hit confirming/Comboing Q

i dont understand why people are alternating between crouching and standing normals in their combos/hit confirms, im still really new at this, someone share some insight.

i mostly play ryu right now

Frame data.

yah it just dawned on me a second ago that its prolly to allow for certain combos but it seems kinda strange.

so my understanding is that it allows for maximum damage in link heavy combos?