Hey, I'm looking at short hop autocancel Nair, and it looks pretty good for covering ledge options. It has enough duration to catch the first vulnerable frame of all four of them (get-up, jump, attack, roll). If you look at the
frame data of the options, you'll see that the first vulnerable frame is 13-35 between every character and every option. With four notable exceptions - Palutena and the three Miis have a first vulnerable frame of 44 on getup for some reason. Excluding that, it's a vulnerability range of 23 frames, and Jigglypuff's Nair has a duration of 25 active frames.
All you need to do as far as timing is wait for them to start moving as part of a ledge option animation before you jump. Though I can see a few issues. For instance, Ledge Jump is the fastest of the options to act out of. It's so quick that, if your reaction timing is too slow, you can trade unfavorably with their own aerials or just miss entirely. Plus in order to catch ledge roll, you have to move yourself away from the ledge. You can only be spaced to hit ledge jump and ledge roll at their first vulnerable frame, never both. But spacing for jump is more optimal, because ledge roll has so much vulnerable endlag for you to react to and punish. If you fail to catch ledge roll with Nair, you'll still auto cancel and have the frame advantage to hit them with dash attack or a grab. Jump only has like two vulnerable frames before they can perform actions, so you want to have it covered. Plus, since you've got them right at the edge, a strong hit of Nair could kill if they have sufficient damage and have chosen Jump. Otherwise, a soft Nair puts them back out there for a stronger offstage edgeguard.
What do you guys think? Optimal ledge coverage, or not good enough to always try?
You're covering one option for free while still leaving yourself more than capable of covering others with Dair, there's literally no reason to not take advantage of that.
