I'll give it to you really brief.
You hit an opponent with 2A. You're now +6 (just making these up, bear with me). This means that you have 6 frames where you opponent is in "hit stun" and cannot block/move/etc. If you do a move that hits within 6 frames then it will connect. Lets say that you cannot chain 2A for the sake of this example. If your 2A has 5 frames to it and hits on the 3rd frame, then there are two frames of startup and it will connect on the third, meaning you could link another 2A. But lets say you didn't want to do a 2A, you wanted to do a 2C, which has 15 frames and hits on the 7th frame. You would not be able to link it in this scenario (we're assuming you cannot chain, which you can in Melty Blood).
Block stun is the same thing, except with blocking. You keep your foe locked in "block stun" instead of "hit stun" meaning you can throw out more moves to keep them locked down.
Basically hit stun/block stun means how long they're locked down, and the "advantage" comes from the fact that you will recover before they do and they will not be able to punish your next attack most likely. The thing about knowing this is that a lot of heavier moves will have a large amount of NEGATIVE frames where you're stuck in the animation and cannot avoid getting hit. Like for instance, if you have a move that puts you at negative frames on block then you're more likely to be hit afterwards.
An example would be a sweep move. Lets say that you 2C someone and you're at -17 now. That gives your opponent 17 frames where they can hit you and you can't get out of it. They could land a big fat combo because you left yourself wide open. However, in Melty you can reverse beat to 5A most times and cut the recovery time to almost nothing, so it's less of a concern in this game than it is in other games.
My examples weren't based on anything in any real game, just arbitrary numbers. I'm sure someone here has a much better knowledge of frame data in MB.
All you should really be concerned about is "what can I throw out that will keep my opponent from moving long enough for me to do something else, and what do I not want to throw out unless I can reverse beat it or cancel it in to something that makes me safe?"
Topic: Hit/Block frame advantage? (Read 3673 times)