Confused about frame-data?

Hello guys. I’m seeking clarification for something regarding frame-data. I’ve read that if a particular move has 3 startup frames for example, that it hits on the 3rd frame. But wouldn’t it hit on the 4th frame? Because that’s when the the active frame period begins. Since it would take 3 frames for the move to startup, it would actually hit on the first active frame which should be the 4th frame, not during startup period. Isn’t that how it is? I just can’t understand how a move can startup in 3 frames and hit on the third frame because woudln’t that actually make that particular move have 2 frames of startup and not 3? Why is this stuff such a headache to grasp…

Pretty sure it’s a matter of semantics and I’ve seen done both ways. Your logic is sound.

Strictly speaking, yes. startup = doesn’t hit, active = hits, recovery = doesn’t hit. So a 3f startup move would become active on the 4th.

However, then you start looking at frame data and see: 3f startup, +2 on block, +5 on hit. 4f startup, -1 on block, +2 on hit. 5f startup, -9 on block, KD on hit., sweep does not combo. This is why many games’ communities list the first active frame twice - once in the total count of active frames, once in the startup: 4f startup, +2 on block, +5 on hit. 5f startup, -1 on block, +2 on hit. 6f startup, -9 on block, KD on hit.

You can immediately see that, links but, sweep doesn’t unless the hits late.

In Virtua Fighter at least the startup+first active frame count is called execution, which is a good distinction that I’d like to see spread.

The pluses are the part that are more confusing for me, talk of moves eating frames, being ahead/behind. 4f startup, -1 on block, +2 on hit - this one is perfect as an example.

Frame data in a nutshell. An opponent in hitstun is helpless. Hit him while he’s in hitstun, and the second move hits, of course. Bam, a combo. Now do that with the second and third move and…

True blockstrings are the same way. Blocking an attack puts the opponent in blockstun - stuck blocking. Connect with another attack while they’re in blockstun, and the blockstun extends.