One of the newest mechanics in Mortal Kombat 11 is Short Hop. By lightly tapping the Up button, your character will jump for a short distance above the ground. After performing a Short Hop, you can use one of two Hop Attacks while in the air. These are overhead attacks that will hit opponents who are crouch blocking.
Hop Attacks can be used as mixups with low attacks. While not very damaging, Hop Attacks can be used to open opponents up who tend to block low a lot. This is especially useful for characters who constantly rely on using low attacks for offense such as Baraka and Johnny Cage.
Hop Attacks are punishable when used up close, but can be made safer by spacing them out. Certain Hop Attacks also have very good horizontal range. These can be used at maximum distance and prevent you from being punished.
Another great way to use Short Hop is to punish throws. On a read if you think your opponent is going to do a throw, you can use Short Hop to avoid the throw. Since your character will be airborne while doing a Short Hop, the throw will whiff and you can whiff punish your opponent. This can be safer than neutral ducking a throw because you will be in the air and it can be more difficult for your opponent to convert into a combo.