Short hop fast fall L-cancel
The short hop fast fall L-cancel, commonly abbreviated as "SHFFL" (pronounced - and sometimes written - like the word "shuffle"), is a combination of advanced techniques that, for most characters, results in the quickest and least laggy way to jump and perform an aerial from the ground in Super Smash Bros. Melee. A SHFFL, per its name, contains the initials of a short hop, a fast-fall and an L-cancel, and an aerial attack that occurs while the user is in mid-air.
When teaching advanced techniques to new players, higher-leveled smashers often emphasize the importance of SHFFLing because the technique reflects a mastery of several important advanced techniques. SHFFLing is highly useful in battle and in competitive play because its speed allows players to use aerial attacks in tandem with ground moves.
Chronological button input:
The last one can be skipped for certain aerials if the aerial is performed very early and has reached its auto-cancel frames or ended completely upon landing. For example, Marth's neutral aerial and forward aerial do not have a very long duration, so Marth will hit the ground after his aerial is over. This can be tested by using a short hop fast fall (without the L-cancel) with the aforementioned moves. The player should land without the usual special effects and minor lag. This phenomenon is known as an "Autocanceled aerial" or an "Early SHFFL", and in Marth's case, an "AC Nair."
Outside of Melee
Short hop fast fall
The short hop fast fall, commonly abbreviated as "SHFF", is a technique in Super Smash Bros. Brawl, Super Smash Bros. 4 and Super Smash Bros. Ultimate that enables the player to perform and land aerials quickly, though not as fast as a SHFFL.
SHFFing plays a large role in the metagames of characters with quick, long-ranged aerials, such as Marth, as it is an effective way of spacing, edge-guarding and applying pressure to the opponent. While technically possible in Melee, it is only used in competitive play if the player is unaware on how to L-cancel or forgets/misses it, in favor of SHFFLing.
In Ultimate, landing lag on most moves have been reduced by a large amount, so the use of SHFFing has been increased, allowing for better pressure utilization.