How do crossups work exactly?

[Vyy]

hi

i am completely new to fighting games and i am glad that someone FINALLY got rid of the unneccesary entry hurdles so i can start to learn one.

i have read the official guide to the game written by sirlin, however one thing is unclear to me.
in the guide it says about crossups something like this:
"an attack where it is hard to determine of u should block left or block right"
i find this explanation a bit unspecific and would like to know how crossups work exactly.
is the blocking direction random?

thank you

[Sente]

To block a crossup, it is not determined by a random direction. To help explain a bit better, here are a couple of examples (most crossup situations happen because of an attack in the air):

If you use Grave’s Hurricane attack in the air (his air B, looks like he’s spinning horizontally) while you’re landing “on top” of the opponent, it can be hard to determine if he’s going to hit you from the left side or the right side. This is a crossup situation. You have to choose either to block left if you think he will hit you from the left side, or to block right if you think he will hit you from the right side. A wrong guess will get you hit.

Another example is Valerie’s BBB combo. The third hit of her B can hit you from the left side or the right side depending on if Valerie presses forward or not. If you choose to block her third B, then you have to guess if she will hit you from the left or right side and then block from the appropriate direction. This is an example of a ground crossup instead of the usual air crossups.

I hope this explained it a bit better! Basically, you have to either know by sharp observation whether to block left or right or you have to read the opponent correctly.

[Zejety]

To put it into more general terms, most cross-ups are jumping attacks.
Because you block by holding away from your opponent/the attack, attacks that hit barely behind (or in front of) the center of your character can be hard to block, because it can be hard to tell whether the hit will register on your left or right.

Not all cross-ups are jump attacks, but most are. Sente mentioned some examples.

[Vyy]

ah okay that clears things up, thanks

[Domon]

to answer your question, they are not random, but they are almost as hard to predicts as they were random.