Negative Edge, Drumming/Piano(ing?)

What is negative edge?

Typically, most beginner 3S players would take it for granted that "one button press = one input." I know I certainly did when I started out. After all, what could be simpler? Press kick, see kick. Press punch, see punch. Doesn't get much simpler than that, right?

As it turns out, the truth is a bit more complicated. In reality, one button press = 2 inputs; one input when you press the button, and one input when you release the button. You can verify this easily by doing to following: press any punch, say jab, then hold it down for the duration of a QCF motion, then release it. You will get a fireball to come out if you did it correctly, despite the fact that you didn't press punch at the end of the QCF motion.

Why does it matter?

One may get the impression from the name - negative edge - that the mechanic is generally not a helpful one, that it's a nuisance of sorts. Although this isn't an entirely accurate portrayal - it does have positive uses which I will get to later - it can often result in moves coming out unintentionally. Here's an example with Ken:

Press and hold cr. MK --> 2x QCF --> see that it didn't hit --> release kick without pressing it again

Whoops! Even though you "confirmed" that low forward was blocked, you end up getting a super you don't want because you held down MK for a fraction of a second too long after the initial button press. If you ever watch higher level players, you'll notice that it seems like they're pecking at the buttons, as opposed to actually pressing them; negative edge is a huge reason why. If you press and release the button as quickly as possible, your chances of inadvertently getting an additional unwanted move go down drastically.

Drumming/piano(ing) the keys - the positive use of negative edge

Although negative edge can have unwanted moves popping out, it can also be used to great positive effecting with a technique known as drumming. When you think about what happens when you press a key, you realize that 2 inputs for one button press means the overall window for having a button press come out is greatly expanded.

Say you're doing a combo with a very tight window, let's say Dudley's f.+HK xx SAIII, which is a 1 frame link. Without negative edge, your end results look like this:

1. Press punch (for the super) on the exact frame it would combo: successful combo.

2. Press punch 1 frame early: nothing comes out. 

3. Press punch 1 frame late: the super doesn't combo, so it gets blocked, and you get punished. 

So if you're off by 1 frame on either side, you end up with a suboptimal result. But now let's take negative edge into account, and assume that the gap between press and release is 1 frame. Now let's reevaluate the 3 scenarios earlier:

1. Press punch (for the super) on the exact frame it would combo: successful combo.
2. Press punch 1 frame early: the input from releasing the button happens on the required frame, so you get a successful combo.

3. Press punch 1 frame late: the super doesn't combo, so it gets blocked, and you get punished. 

Now the success rate has gone up twofold, because you've effectively doubled the window in which you can input the super and get a successful combo. Note that this only helps if you 1. err on the side of inputting the super early; there is no magic cure or technique that will allow late inputs to somehow give a good result, and 2. press and release the buttons very quickly.

In fact, on most supers you can go a step further and press all 3 punch or kick buttons, effectively giving you 6 inputs for the super. To maximize the window in which these inputs are spread out, you don't want to hit all 3 punches or kicks simultaneously (a common mistake among beginners). Instead, you want to more or less riffle your fingers across the buttons, as if running your fingers across a set of piano keys very quickly (hence the alternative name "piano(ing)"). There should be a slight gap between each press and release, which results in 6 independent but very close (temporally speaking) inputs. Thus a 1 frame window becomes a 6 frame window, and you find that those 1 frame links which seemingly require superhuman timing are now a piece of cake. It should go without saying that you can't use this technique on supers that are button specific, like Makoto's SAII.

In fact, it generally becomes a habit on virtually all combos involving supers to drum all 3 punch/kick inputs, even when the timing is not particularly strict. It's a very useful technique that will increase your consistency on tight combos significantly, so it's well worth mastering.