I feel like I've come to realize the importance of
contrast.
As you get better, you play better opponents, and many times, you'll, without trying to, condition a response out of them. This is because they pick up on a certain pattern or yours, consciously or not, and they respond with some option.
Of course, us Samuses being the kind of people we are, try to pick up on their patterns and punish them accordingly. But then you see Hugo make some kind of sick hard read that you never would've expected, and you go... how'd he do that?
This is commonly seen when high level Samuses get ridiculous grabs that no one thinks should work. A lot of lower level Samuses, myself included, don't have a good explanation of why these reads work. How did he know the opponent was going to shield there? I watched the opponent too, he didn't shield in that situation before, was it just some kind of transcendant read?
I was watching the wrong player.
Top players, mentally, are aware of their own movements and habits. They make little changes to contrast what they do so that the same option their opponent throws out doesn't cover both things.
People refer to conditioning a lot, but this is completely separate.
For example, let's take some of Westballz shield pressure. Dair->double shine->waveshine in place->doubleshine->wavedash back
By changing the rhythm of his shines, Wes purposely lets his opponent have the opportunity to do something out of shield, and sets up an option to cover that. He sometimes will sometimes double shine->wave doubleshine, etc etc, his pressure has many variations, and the reason is contrast. Because of his options, there isn't an out of shield option in the game that you can use to beat all of his pressure choices.
This concept is embodied in Mango as well. Why is it that no one can shield pressure like Mango?
At least, part of it, I think, comes from the fact that he's a high level floaty. He's taken the concept of contrast that we use to pressure people normally, and applied it to Fox. His movement is confusing, and the aerials he throws out all have different timings for punishments, it's hard to beat simply because there's no simple way to do it, his pressure is very close to completely gray. It doesn't focus on one move, or one option, or one thing.
I think that if you're already a technically sound Samus who understands spacing and knows matchups decently, the next step would be to start to understand your own movement, how it affects your opponent, and use that to develop contrasting patterns.
Just look at Hugo:
https://www.youtube.com/watch?v=Rjlc1k2qxs0#t=3m59s
Technical flub aside, Hugo got away clean from the dsmash. Now he knows his opponent will have a high likelyhood of shielding, or coming in for an attack because of his previous dancing. He doesn't have to observe his opponent, he just looks at his previous actions, and from that, he surmises what his opponent will do next. He's been weaving in and out, he just made a technical error. A lot of times, that's a trigger for the player to come in. However, his opponent whiffed a dsmash, which puts him at frame disadvantage, and players when they whiff a move, have a tendency to shield(this assumption is often absent in Shroomed, which is my theory as to why Hugo started to lose to Shroomed, he got baited with whiffed moves). So Hugo wavedashes back in, to make it look like his previous pattern, and then instantly deviates with a grab, contrasting his previous options of jab cancel, tilt, and dsmash, all of which would've been punished by shield. It wasn't really a sick read, or a crazy grab, it was just Hugo realizing that he'd been doing things that shielding is good against, and it was time to do something that shielding wasn't good against. The fact that the opponent didn't shield is irrelevant because the grab covered ground approach options as well.
Anyways, if I'm wrong about this, Hugo, lemme know, I'm making a lot of assumptions here, but it makes a lot of sense to me.
tl;dr a lot of smart plays can be made by watching the opponent and reacting accordingly, but smart plays can also come from watching your own patterns and choosing options that can't be covered with the same options from your opponent.