from the SRK wiki:
Fireball recovery in HDR, for the most part, depends on the button you threw the fireball with. However, for characters with 2 types of fireballs (Ryu, Sagat and Akuma), it doesn’t depend on the button you threw the fireball with, but on the button of the last normal attack you performed (either complete or canceled) before throwing the fireball. There’s a widespread misconception that normals only affect fireball recovery if you kara-cancel the normal into the fireball, but this is incorrect. The DreamCast port of ST, which HDR is based on, fixed this bug for Akuma’s Hadokens specifically, but left it in for Ryu and Sagat.
This is an excerpt of AWJ’s original post.
- Ryu’s Hadoken, both Blue and Flame, have recovery times of 40/41/42 based on prior normal attack. Example: a whiffed Jab followed by a Fierce Hadoken will give a Jab Hadoken recovery.
- Sagat’s Tiger Shot recoveries are affected by prior normal attack: 40/41/42. Example: cr Forward cancelled into a Roundhouse Tiger Shot will give a Forward Tiger Shot recovery.
- Akuma’s recoveries are unaffected by prior normal attacks for both Blue Hadokens (all 39) and Flame Hadokens (61/69/79).
- Ken is unaffected by prior normal attack and his Hadoken recoveries are 39/40/41 based on the strength of the fireball.
- Dhalsim is unaffected by prior normal attack and his Yoga Fire recoveries are 39 across the board.
- Chun Li’s Kikoken has different recovery based on the normal that was done just before it. Cancelling or whiffing a Fierce or Roundhouse will shorten the length of the recovery.
- All other charged fireballs are not affected by prior normal attacks.