Research:Street Fighter II
Street Fighter II is considered the title that defined fighting games as we know them, and as a result many mechanics and concepts found both in following Capcom fighters and those from other companies were established here. On the other hand, as an early, experimental title, it also contains many of its own unique quirks and idiosyncrasies.
Hitstun[edit]
Hitpause[edit]
Also known as hitstop, this is the short "freeze" that happens immediately upon impact of a hit, before the opponent goes into hitstun and the attacker begins the follow through of their attack. Hitpause in SF2 is generally 14 frames starting immediately after the frame of collision, but some phenomena exist with regards to the opponent's hitpause that can lengthen or delay it:
Firstly, in all pre-Super Turbo versions, the attacker's hitpause begins on the very first frame after the frame of collision. However the opponent will continue their previous course of action for one frame after the frame of collision before their hitpause begins (although in the event that they are in a grounded hit/blockstun state, no knockback will be applied on this frame). This has the net effect of granting the attacker an extra frame of frame advantage. This property is retained if the attacker is an "Old" mode character in Super Turbo, or if the attacker is any of the non-Super Turbo modes in Hyper SF2.
Secondly, hitting an opponent who is in a grounded idle state (idle stance, walking, jump start or land, idle crouch or stand/crouch transition, idle blocking, basically anything not midair, attacking or in a stun state) will have said opponent's hitpause extended by one frame to 15. Unlike the previous phenomenon, this applies to all versions of SF2.
Supers cause an 8 frame hitpause for the attacker and a 10 frame hitpause for the opponent. The aforementioned extra frame for opponents in grounded idle states also applies, lengthening it to 11 in that case.
Ground Hitstun[edit]
Standing and crouching hitstun and blockstun almost always fall into one of three categories: Light, Medium or Hard. Normal attacks performed by a grounded opponent against another grounded opponent will inflict their respective strength's hitstun or blockstun. Jumping normals will always inflict Light hitstun against a standing opponent. However the hitstun inflicted against crouching opponents as well as the blockstun inflicted against a blocking opponent will correspond to the normal's strength. Specials generally inflict Hard stun.
Light stun lasts 11 frames, Medium lasts 16, and Hard lasts 20. The knockback experienced during the stun comes from an arbitrarily predefined table that tells the opponent how many pixels to move on each successive frame of stun:
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Light | 4 | 4 | 4 | 4 | 3 | 3 | 3 | 2 | 1 | 1 | 1 | |||||||||
| Medium | 6 | 6 | 6 | 5 | 5 | 5 | 4 | 4 | 3 | 3 | 2 | 1 | 1 | 1 | 1 | 1 | ||||
| Hard | 8 | 8 | 8 | 7 | 7 | 7 | 6 | 5 | 5 | 4 | 3 | 2 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
Note that Supers are capable of inflicting a special type of hitstun that uses the Light hitstun animation and lasts for 20 frames, but has no knockback whatsoever, leaving opponents completely stationary for its duration.