Figuring out optimal punishes.

[Hills]

I was thinking about how other fighting games deal with frame data and wanted a way to know whether or not a move is safe on shield/what you can punish moves with optimally. In other words, how plus or minus a move is on block. Right now I'm going to ignore power shielding as well as spacing.

Shield info: http://smashboards.com/threads/shields-in-smash-4.381183/
Shield stun info: https://www.reddit.com/r/smashbros/comments/2vh3fj/so_a_mod_on_smashboards_did_some_tests_with/

You need the difference of the hit frame and the first act frame. You account for the shield stun and that should be how unsafe a move is, right?
Example:
ZSS fsmash's last hit ends on frame 28, FAF 62, shield stun is 4, it takes 7 frames to drop a shield. 62-28=34 frame between when the attack hits and when ZSS can act. The defender can't do anything for 4 frames (shield stun from an 11% move), so you have 30 frames to do an out-of-shield option. Shield drop time is 7 frames, so you have 23 frames to do a normal move (a non-out-of-shield option) after waiting for your shield to drop.
Aerials are more complicated with some that auto-cancel at certain points. Assuming the aerial doesn't auto-cancel, the defender would have an advantage based on the landing lag frames, plus the frames between when the hit box ends and the attacker hits the ground.

Am I doing this right? Is this something other people have calculated somewhere already and I just haven't found it?

 

[Zapp Branniglenn]

You're on the money for calculating how much time your opponent has to punish Zero Suit's attack, but there's one more piece of information that I don't blame you at all for not knowing and it directly relates to your choice of move in your example. In Brawl and Smash 4, moves with a hitlag modifier above 1.0 create more shieldlag (that's the hitlag equivelant for when a move is blocked rather than hits the target) for the attacker than the defender. Zero Suit's Fsmash has a modifier of 1.6, so it is very disadvantaged on block. It's a very annoying and unfortunate fact that's very prominent on certain characters like Marth's tippers. And if a move has an electric effect on it, it suffers from a 1.5 hitlag modifier that isn't explicitly stated in the game's data. Zero Suit's Nair is an electric attack, and is thus less safe on shield by freezing her longer than the opponent blocking the move. In the most recent patch, they alleviated these effects by a bit, but didn't remove them entirely. For example, Marth's Fsmash tipper (1.5 hitlag modifier) freezes him for 14 frames instead of 18 before the patch, while the defender is frozen for 11 before beginning to suffer shieldstun. Electric attacks with their innate modifier were not effected by the patch.

And this effect also works in reverse. If a move possesses a hitlag modifier of less than 1.0, then the attacker suffers less shieldlag than the defender. A good example is, again, Marth's attacks. Non-tipper hits have modifiers of around 0.7, making them safer on shield. Check this page out and the pages preceding it for formula info and more examples. And this is the link I use for looking up which moves have a hitlag modifier. But keep in mind the frame data presented in that link is only up to date to version 1.04, so cross reference with our patch history threads to get accurate data on active frames and etc.