Smash directional influence: Difference between revisions

'''Smash directional influence''' (commonly shortened to '''Smash DI''' or '''SDI''', and officially known as '''Hitstun Shuffling''' since ''[[Super Smash Bros. 4]]'') is a mechanic that allows players to slightly alter their position during [[hitlag]] from being hit by an attack. Tapping the [[control stick]] (and/or [[C-stick]] in ''[[Super Smash Bros. Brawl]]'') in any direction during the 2nd hitlag frame and onward will slightly move their character in that direction, allowing them to potentially escape multi-hit moves or certain [[combo]]s. SDI can also be used to move into a wall or ceiling in order to [[tech]] near-instantly or to (very minimally) increase the distance from the [[blast line]] that the attack is about to send them towards.

Whenever a character is hit on the ground by an attack that does not lift them off it, such as a weak [[meteor smash]] or move that launches at the [[Sakurai angle]], they can only leave ground horizontally, not vertically. This prevents them from SDIing upward and going airborne before getting launched by the attack, potentially allowing them to immediately land and cancel [[hitstun]]. When grounded, the horizontal component of a diagonal SDI vector still moves the character, only vertical component is negated. Consequently, quarter circle SDI and other methods to perform multiple SDI inputs still work. In ''Ultimate'' when hit with a move that will lift the victim off the ground, it is possible to SDI upwards only if the first SDI input is made on exactly frame 2 of hitlag, and it is in an upwards direction. Doing so lifts the opponent off the ground during hitlag, allowing for further upwards SDI inputs to be made. Notably, this allows opponents to jump out of fast hitting moves such as {{SSBU|Ryu}}'s down tilt which would otherwise force a landing during hitstun, before hitting the ground, as they will be launched from higher up, and thus the hitstun will end before they land. However, due to the frame perfect timing required, which also demands a correct prediction of what move will hit the victim and on what frame, this has little to no utility in realistic circumstances.

As SDI is performed during hitlag, a move is easier to SDI the more hitlag it inflicts, and impossible to SDI if it has less than two frames of hitlag. This is also why the mechanic is more effective against multi-hit moves, as each hit puts the opponent in hitlag and thus extends the total amount.

'''Automatic smash directional influence''' ('''ASDI''' for short) is a weaker variant of SDI. Once a character's hitlag is over, they shift slightly in whatever direction the control stick is currently held, by a shorter distance than an SDI input. If the C-stick is also being held in a direction, it will override the control stick's input, allowing the player to [[DI]] in another direction simultaneously. ASDI is significantly less useful than regular SDI and is generally ignored, as any stick position during this time is likely to be attempted at regular DI. In ''[[Super Smash Bros. Melee]]'', however, it is an important factor in [[crouch canceling]]. The downward shift from ASDI down may allow a character to land on the ground immediately. If the character wasn't knocked down, the landing cancels hitstun, and thus allows them to retaliate against attacks much quicker than usual.

Similar to SDI, '''shield SDI''' (officially named '''Shieldstun Shuffling''' by the [[tips]] in ''[[Smash 4]]'' and ''[[Ultimate]]'') is a mechanic that allows players to move slightly when their [[shield]] is hit. It is nearly identical to SDI in its function and how it is performed: during hitlag (and thus before [[shieldstun]]), players can tap or hold a direction on the control stick to shift along the ground, with each shield SDI pulse covering 2/3 (or exactly 0.66× in ''Melee'') of the distance of a regular SDI pulse. However, contrary to SDI, shield SDI can only be applied horizontally, and vertical components of control stick inputs are completely ignored. Thus, techniques such the quarter-circle SDI wont result in multiple shield SDI inputs. Shield SDI is especially useful to escape some grounded multi-hit attacks, most notably [[Peach (SSBM)/Down smash|Peach's down smash in ''Melee'']].

There is also '''shield ASDI''', which has the already familiar relation to shield SDI: It's half as effective as shield SDI, and is applied on first frame of shield recoil, after hitlag. Since shield SDI is already less effective than regular SDI, shield ASDI is virtually imperceptible in most cases.

In ''Smash 64'', ''Melee'' and ''Brawl'', SDI is very effective, especially in the latter due to attacks possessing more hitlag. In these games, every SDI pulse moves a character 6 units in the direction chosen, or 3 units with ASDI. With enough pulses, SDI allows characters to escape a majority of multi-hit moves before they can connect their final, usually stronger hits; as a result, multi-hit moves with weak linking hits and where the character remains stationary, such as [[rapid jab]]s and [[Samus]]' [[up smash]], are regarded as ineffective due to their poor reward and extreme vulnerability if they are escaped, while others that allow movement during their use, such as [[Fox]] and [[Jigglypuff]]'s [[down aerial]]s, require careful [[spacing]] of their hits to either land all of them or get the opportunity to [[punish]] opponents after they SDI out.

Beginning in ''Brawl'', all attacks have an '''SDI multiplier''' attached to them, which affects how far opponents can shift via SDI when hit by them. This also affects ASDI, but not shield SDI. For most attacks, this multiplier is 1×, allowing them to be SDIed normally. However, certain multi-hit moves have lower multipliers, reducing their SDI ability to the point they can connect more reliably; examples of such moves are the linking hits of {{SSBB|Zelda}}'s [[forward smash]] and [[up smash]], which have SDI multipliers of 0.5× and 0.1× (respectively) allowing them to connect much more reliably than in ''Melee'', where even ASDI alone was enough to escape them. Likewise, some moves with noticeably long hitlag use an SDI multiplier of 0×, effectively making them impossible to SDI, and preventing characters from shifting long distances away as they are hit; examples are the [[sweetspot]]s of Zelda's [[Lightning Kick]]s, as well as the [[tipper]] of {{SSBB|Marth}}'s forward smash. Conversely, some multi-hit moves have higher multipliers, such as the linking hits of {{SSBB|Mario}}'s down aerial and {{SSBB|Pit}}'s [[neutral aerial]] having multipliers of 1.5× and 1.4× (respectively), allowing characters to SDI out of them even more easily.

Because of the drastic [[nerf]]s to SDI in ''Smash 4'', there are extremely few attacks against which it is particularly effective, namely {{SSB4|Ryu}}'s light [[up tilt]], and most infamously {{SSB4|Bayonetta}}'s [[After Burner Kick]] and [[Witch Twist]] beginning in update [[1.1.6]], due to their SDI multipliers of 2.5× and 2× (respectively), long hitlag, and ability to otherwise lead into guaranteed combos that can both rack up significant damage and KO. In other cases, it is generally considered useless due to its negligible effect without an exorbitant amount of SDI pulses, and disregarded in favor of [[DI]] whenever possible. Likewise, ASDI and shield SDI have lost all of their practical usefulness due to their even shorter distance, especially the latter due to not being affected by SDI multipliers that could otherwise increase its distance.

In ''[[Super Smash Bros. Ultimate]]'', SDI retains its shorter distance from ''Smash 4'', and has been further limited. Each time an SDI input is made, the next input will not register until 4 frames later, and if any SDI inputs occur during these frames, the latest one will be buffered when another SDI pulse is possible. However, as it is difficult for human players to consistently SDI at such a fast speed, this change is considered somewhat minor in standard play, but makes quarter-circle SDI much less effective. Notably, this limit does not apply to shield SDI, making it comparatively stronger than in ''Smash 4'' due to the increased [[hitlag]] in ''Ultimate''. Automatic SDI has also been weakened drastically, now being essentially negligible. Additionally, due to the severe nerfs to {{SSBU|Bayonetta}} and {{SSBU|Ryu}} from ''Smash 4'' (especially the former), who were the main characters SDI was impactful against, the technique is generally even less useful; as of the current [[metagame]], its only notable use is to improve the chances of escaping {{SSBU|Pichu}}'s "lightning loops", which involve continuously dragging opponents down with the setup hits of its [[back aerial]] and launching them back up with its [[up tilt]]. Additionally, due to a new mechanic in ''Ultimate'' which increases the strength of SDI over time against consecutive grounded hits, SDI has some use for escaping rapid jabs as well, most notably allowing players to escape Isabelle's jab wobble after having been hit a few times. Much like DI, SDI has gained a visual indicator when performed, allowing players to see which direction their opponent is going.