The idea of a meaty attack is so that you get extra hit-stun. It basically means that if you hit an opponent with a meaty attack, it has similar properties as a counter-hit. This is done by making the last active frame of an attack hit, so you have the normal amount of hit-stun with less recovery.
Let’s imagine a move has [3 Start-up frames]; [3 Active frames]; [5 Recovery frames]; and deals [9 frames of Hit-stun]
Start-up frames (3) -> Active frame 1 -> Active frame 2 -> Active frame 3 -> Recovery frames (5)
– The idea is that if the first Active frame hits, it deals X amount of hit-stun.
Active frame 1 / Hit-stun frame 1 -> Active frame 2 / Hit-stun frame 2 -> Active frame 3 / Hit-stun frame 3 -> Recovery frames (5) -> Hit-stun frame 9
– In this timeline, you’ll see that the Hit-stun frames started on [Active frame 1], and the frame-advantage is +1
If we imagine that the opponent was hit on [Active frame 3] we see something interesting.
Active frame 1-> Active frame 2 -> Active frame 3 / Hit-stun frame 1 -> Recovery frames (5) -> Hit-stun frame 7 -> Hit-stun frame 8 -> Hit-stun frame 9
– In this timeline, we have a frame-advantage of +3, allowing us to have new combo ability.
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What MingoDynasty is talking about is using an attack to that it’s active frames overlap with an opponents first wake-up frame, which means that should a non-invincible Reversal move some out, it will be hit.
In Third Strike we used to use meaty attacks to punish Reversal attempts, but almost everything in this game has invincibility frames on it. Interestingly enough though, if you did a meaty attack on Dudley with no meter, and he tries to DP, he will get stuffed.
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The main application of using meaty attacks in SF4 is to punish wake-up crouch-techs, or to increase block-stun on certain moves. Unfortunately enough, normals in SF4 have too many recovery frames so you can’t do a meaty and recover in time to block a DP.