What to do on opponent knockdown?

So whenever I play and knock someone down, I tend to get away from my opponent. I guess since I play Ryu I get away to throw and zone with fireballs. I’ve watched some SF 5 tournaments and notice EVERYONE after they knock their opponent down they do the complete opposite of me, they dash towards their knocked down opponent and keep attacking. So, is this how I’m supposed to play? I mean is getting closer to my opponent better than getting away from the opponent on knockdown? What are the advantages etc?

I’ll try to keep it simple and just give the basics on why it’s good to advance when your opponent is knocked down.

You want to pressure your opponent. When he’s knocked down, you have the advantage. Without going into frame data or whatever, he basically has to guess what you’re going to do. Fighting games are built on a sort of rock-paper-scissors structure. Strikes beat throws, throws beat blocks, and blocks beat strikes. Granted, it’s actually much more complicated, but those are the fundamentals at least. Now, if we’re both standing up at the start of the round positions, I have all my options. I can jump, I can move backwards or forwards, I can attack, I can throw, I can block. But when you knock me down, I’m more limited. I can’t move backwards or forwards. I can’t attack, throw or jump until I get up. But my opponent has all of his options, and they’re all less dangerous because I can’t do anything about it for a little while.

This is where you get the concept of a meaty. Without going into frame data, the basic idea is that you throw out a big move that’s active for a relatively long time while your opponent is getting up. This timing should be so that he’s getting hit right as he stands up again. If he tries an attack that isn’t invincible, the start-up on his move means he will get hit by your move before his can come out and eats a counter-hit. If he throws, the same thing happens. He won’t have time to jump out of it either. If he blocks, you are at more of an advantage than normal because of how move recovery and blockstun works and he shouldn’t be able to punish you.

It’s also easier to cross your opponent up while he’s knocked down. IE, hit him from the “wrong” direction by jumping over him and hitting a move as you move over his center, forcing him to block by holding forward instead of back. A lot of characters have jumping attacks that are really ambiguous, making your opponent essentially guess which way to block unless he’s really good at judging jump arcs. Throws are also important once your opponent figures he’s just going to start blocking your meaties. As are neutral jumps, meaning you just jump straight up in the air to beat throws and most attacks.

If you combine these, you now have the meaty, the throw and the cross-up. Even just with these tools the guy who is knocked down has to start making guesses. If he blocks, he might eat a throw or a cross-up (not to mention having to guess if he should block high or low if your character has somewhat fast high attacks). If he throws and you jump or meaty, he eats a ton of damage. If he attacks, the same thing might happen. Jumping will only beat a throw, but it’s also one of few options he has to beat a throw. If you back off after knocking your opponent down and just throw fireballs, none of this guessing game comes into play because all the knocked down party has to do is block and take a tiny bit of chip damage. Hence why you mainly see Ryus in V-Trigger throw meaty charged fireballs, because it sort of beats block (but not really).

There’s also the larger game of controlling space. Being in the corner is rough. Remember what I said about my options of moving, jumping and all that? Well, when I’m in the corner, I can’t really move backwards, so my options are forward, attack or jump. This makes my gameplan more restrictive and easier to react to. Not to mention that a lot of attacks are way harder to avoid in the corner since you don’t have space to maneuver, and combos tend to be bigger and more damaging since you can’t get knocked away any further. Getting your opponent in the corner is a great thing, so you don’t want to give up a ton of space willingly.

when your opponent is knocked down their options are dramatically limited and yours are not.
so this puts the opponent in a challenging situation where if they just stand up they can easily stand up into a setup or a hit or anything.

you want to take advantage of this mental pressure by doing something which doesn’t telegraph your response to the knockdown, forcing them to guess your intentions and possibly make a poor choice.

at far range your choices are very limited with every character so you are telling your opponent you’re just going to let them stand up or throw a fireball, both of which are not really much of a threat and let catch their breath.
at close range you have many more options which means a lot more guessing for your opponent. this is an advantage for you.