What does frame-advantage and frames mean? - Super Street Fighter 4 Question - sf4answers

Frames are, in short, the smallest unit of time that anything happens in Street Fighter (and usually, fighting games in general). Like a cartoon or any other animation, the motion on the screen is made up by lots and lots of very short frames. In Street Fighter 4, one frame is 1/60 of a second.

Every move has a predetermined speed at which it starts up (before the attack can hit anything, like when your fist is being thrust forward), when it's active (the time when you can hit somebody with it, like when your fist is fully forward), and when it's recovering (the time that you can't do anything after you perform your move, like while your fist and arm retract). Each of these lengths of time can be measured in a number of frames. For example, if Balrog's crouching jab has a three-frame startup, that means that from the time you press the button, three frames (3/60 of a second) pass before the move will become active and be capable of hitting your opponent.

While every move has recovery time in which you cannot do anything, connecting with an attack (either hitting your opponent or being blocked) also puts your opponent into a small amount of time where they cannot do anything either. This is called "hit stun" or "block stun", respectively. In Street Fighter 4, hit stun is longer than block stun. Connecting an attack on an opponent will oftentimes leave your opponent in "hit stun" even after your move has finished recovering, leaving you free to follow up with another attack to create a combo.

"Frame advantage" is a natural consequence of the above concept. Let's take another example -- Guile's crouching jab, on a frame data chart, is listed as "+1" on block and "+4" on hit. What this means is that when you strike an opponent with Guile's crouching jab, if your opponent blocks it, you will recover from the jab one frame before your opponent will recover from their block stun. Similarly, if your jab connects, you will recover 4 frames before your opponent will recover from their hit stun. As an easy example, you could then land another crouching jab (which has a 4 frame startup) if you executed it immediately after recovery of your first jab and your opponent will be hit by it without having a chance to do anything. It should be noted that these figures assume that you connect with the first active frame of your attack -- if you do a meaty attack (an attack that connects midway through its active duration), then you will recover from your move even earlier than your opponent will, which will grant you even more frame advantage. (You can also cancel the recovery animation of attacks into other things, but that's a separate topic.)

Frame advantage is also important when figuring out what moves can beat what moves of your opponent. Let's imagine a hypothetical scenario where you've just finished a block string and you're now at +1 frames. This means that the earliest time that you can do anything is 1 frame sooner than the earliest time that your opponent can do anything. If, while at +1 frame advantage, you throw out a move with a 4-frame startup, that means that your opponent can only beat your attack if they use a move that has a startup of 3 frames or less (4 frames - 1 frame from frame advantage = 3 frames). So, say, Balrog's crouching jab (3 frames) might trade with your 4-frame move in this situation. (This is ignoring hitboxes.) If your opponent used a slower move (say, a 4-frame move versus your 4-frame move), your move would hit them before their move becomes active (1 frame before, to be precise, from the +1 frame advantage), and you would even register a Counter Hit, to boot (because your opponent was in the process of sticking out a move), which causes extra damage and hit stun (depending on the strength of the attack).

For more information, I highly recommend reading a general-purpose frame data primer, such as this one on EventHubs.