I guess this post will be dedicated to Comic-Z.
I've gone over staggers and suki traps before, as well as mindgames and psychic DPs, but I guess rewording everything couldn't hurt.
The act of leaving a gap between attacks is often called staggering, because the rate/tempo of the attack inputs is "staggered". The idea behind this is, if you were to string 10-20 attacks as fast as possible (airtight) against an opponent then there's basically zero chance for them to get hit on any of these attacks unless some of them are overhead/lows. However, if you leave a frame gap in between attacks then they at least have the potential to be hit, because they leave blockstun.
However, even if there is a gap between attacks, what motivates the opponent to drop their guard? Why would an opponent try to mash out an attack between hits, jump, throw, backdash, or whatever?
Well, fear. The whole concept of fear is basically synonymous with "mindgame". It is not a mixup, it is the act of tricking/forcing your opponent into doing what you want them to do, like using a psychic DP.
It is not simply mathematics, and you can't rely on variation and moderation to pull through. That's not how it works. You have to actually pay attention to what you and your opponent are doing, and try to get into your opponents head.
If you get an opponent blocking a lot, you must make them afraid to rely entirely on blocking. If you exert that you have a strong high/low and melee/throw mixup game then the opponent will begin to fear the risk of getting hit by these actions that counter blocking (or incorrect blocking). The common reaction to this is to start option selecting with ghetto defenses, such as mashing, chicken blocking (jump block), backdashing, and attempting reversals and such. Knowing this, you can go back to specifically countering/abusing these option selects with staggers, which beat all this stuff.
The reason this can't be based on mathematics and variation is that doing so is basically guessing. And when you're guessing, you're prone to guessing wrong. Educated guessing, though it may be, is still prone to potential failure -- though is often necessary anyway, especially in netplay.
Instead, to use these techniques effectively you have to pay close attention to what your opponent is doing and even thinking. Often, if you just assume you know exactly what your opponent is going to do, or is not going to do, you may guess wrong. However, rather than guessing you can force situations where you know what the result will be. If you notice that your opponent will often react a specific way to a specific situation, then you can recreate the situation and directly counter their predictable action.
Predictability being the key word there. In my opinion, every truly predictable action does or should have a direct counter to it. Thus, if you really want to get inside your opponents head you'll need to observe what their habits are.
This is one of the major backbones to developing/learning/progressing in fighting games: breaking down habits. If two players play frequently, but never really pay attention to each other's habits, they are not likely to learn or progress at all. Often, the ones who pay no attention to habits at all are the ones that become "Stuck" at a certain level of play and are unable to improve.
Learning to beat/counter things is really essential to fighting games in general. But it is not always just your opponent that you're trying to beat/counter, you also have your own habits to deal with, and can at times be your own worst enemy.
We are not all fast learners though. Some of us take a long time to notice certain things, while others notice them instantly. And even when we notice them, there's different rates at which we correct them. The most interesting players are the ones that notice what hit them and why very quickly, and either experiment or create interesting ways to prevent it from happening again or completely countering the situation in the first place.
But while some of us are not really so keen, a good place to start is at least to "take a moment" and think about what hit you and why, or what hit the opponent and why it worked.
Personally, I'm unable to do that during the course of a set. I need a break between matches in order to "take a moment". But this is often why I post my own matches on youtube. It's not really just to showcase the game or my matches, I actually watch all my matches and try to analyze what exactly happened during the match. And hopefully I can see where I'm lacking and what my habits are, so that I can adjust.
In my opinion, reviewing your own gameplay is really crucial, especially if you are unable to actively see mistakes from your opponent and yourself during a match, and develop ways to adjust or counter these situations while actually playing.