The numbers on next to shield stun indicate the frames the opponent is in shield stun.
5 frames with the hard hit. 2 Frames if you hit on the weak tail end of it.
Optimal shield advantage is how many frames you are ahead of your opponent (or vice versa) to follow up with. -4 means that if you hit with the hard part of Peach's bair and then land, your opponent will have 4 frames in which they can react without you being able to do anything.
Optimal Shield Drop Advantage: How many frames you or your opponent have to follow up/counter after the opponent shields an attack. This number is assuming your opponent has not PS'd the move and reacts on the soonest possible frame.
A +3 means that you (the attacker) will have three frames to follow up on the opponent without them being able to do anything because they're in their shield drop animation. This number assumes the opponent has not PS'd the attack (if they PS their shield drop animation has IASA frames)
5 frames with the hard hit. 2 Frames if you hit on the weak tail end of it.
Optimal shield advantage is how many frames you are ahead of your opponent (or vice versa) to follow up with. -4 means that if you hit with the hard part of Peach's bair and then land, your opponent will have 4 frames in which they can react without you being able to do anything.
Optimal Shield Drop Advantage: How many frames you or your opponent have to follow up/counter after the opponent shields an attack. This number is assuming your opponent has not PS'd the move and reacts on the soonest possible frame.
A +3 means that you (the attacker) will have three frames to follow up on the opponent without them being able to do anything because they're in their shield drop animation. This number assumes the opponent has not PS'd the attack (if they PS their shield drop animation has IASA frames)