I can't tell if this is clear or not, give me feedback.
Yoshi
Favorability
3
Good Stages
Final Destination
Smashville
Green Hill Zone
WarioWare
Fountain of Doom
Bad Stages
Yoshi’s Island
Dreamland
Yoshi’s Story
Battlefield
Yoshi’s movement game thrives on platforms, so Zelda can work fairly well on stages that are open and flat. Depending on how quickly you want to death combo Yoshi, you can take a little risk and go Warioware or Green hill, or even Yoshi's story, because you might also die relatively quickly.
General Strategy
This matchup is best played with a Din’s around you at all times. I think most matchups are best that way, but in this situation, it will force the Yoshi to concentrate on the Din’s in some situations when he should be focusing on you, and that will lead to a free punish. If he doesn’t focus on the Din’s, you can tap him with it, and that gives you even a nominal amount of hitstun to work with. He can double jump through it though, so it isn’t phenomenal for edge guarding, but tacking on the extra percent can only help.
From the moment you start, you should be looking for a Grab or an Usmash. Play the neutral, poke with Din’s and Telecancel about until you find the opportune moment to do Zelda things.
Once you get the grab, telecancel to tech chase and punish to the best of your ability. If they DI improperly, an Usmash will do just fine. Yoshi’s on the shorter side of things, so it’s a little tougher to snag him from the side with Usmash. Once you get an Usmash, you can follow it up with another Usmash if they’re below 15%, or you can Nair, and continue it with a Din’s, possibly. If you want to end it and set back to neutral, or don’t have the time to Nair, Uair works fine too. Sometimes they’ll just be in range to kick out of Usmash, so don’t be afraid to go for that too. Standard Zelda combos are just fine here.
Be wary of your tilts. Yoshi’s grab is quite long, and will grab you out of a lot of things you may want to do, so monitor their positioning when going for an Ftilt. Additionally, Yoshi can duck under your Ftilt at a certain range, and punish with his set-knockback Dtilt, which gets to be a pain.
Yoshi is looking for a grab or pivot grab on you, so a well-timed Nayru’s will stuff his approach. If he’s coming at you from the air, don’t you dare Nayru’s. because you’ll eat a Nair or Fair.
Spacing your every move is incredibly important in this matchup. A moment of sloppiness will result in a grab, nair, dtilt, egg hit, or egg roll hit for Yoshi, and that puts you at a disadvantage. Grab him out of his egg roll, by the way. Pivot grab works best, but it doesn’t have to be. You can kick him out of things, but it has to be very precise, or else he’ll snag your foot with a hitbox.
Never be shielding too much. I know as Zelda it's usually a good idea, but don't. There are so many options that he has against you that if he catches you in shield, he can either command grab you from the air, use Dair for massive shield damage, or shield poke with Dtilt or the stars of his Down B.
Once Yoshi gets a grab, he can combo you for a little bit, even with "proper" DI.
His double jump will screw you, if you don’t know when he can use it. Be very aware of when he is in hitstun
Yoshi is also one of those characters that is very awkward to edgeguard, such as Sheik, Peach, and the like. You can hit him with a kick, but you need to wait for his super armor to end if he double jumps. If you can hit him before that, he should really already be dead.
Things to look out for
Pivot Grab – Yoshi’s Pivot grab is incredible and will get you if you aren’t paying attention. Yoshi’s throws also give him quite a few follow up options. Dthrow combos into just about anything, even if you DI away. If you DI behind him, then he can still nail you with an Uair, which acutally kills at higher percentages. 110% even, on some stages. Mashing jump if they are following you is probably not to bad of an option, and then finding your way out somehow is the next step. Obviously teleporting down works, but consider the Nayru's glide or even a falling uair/nair mixup.
Fair - When teleporting to recover offstage, Yoshi can very easily Fair you, which is a meteor, so be sure to cancel it if by some fluke he clips you.
Nair – Yoshi’s Rising Nair is difficult to deal with, and can kill fairly early on smaller stages. Don’t let it get the better of you.
Dair – just thought I’d mention it, but if all the hits of Dair connect, it does 56%, but it can be easily SDI’d. Just thought I’d warn you.
Dsmash – If you teleburn Yoshi while he’s crouching, he can easily cc and dsmash you, so be wary.
Egg toss – don’t bother reflecting these with LC Nayru’s. Just keep calm and carry on… to punish him for throwing an egg at you.
Video
https://www.youtube.com/watch?v=xZTROIgWB6g
https://www.youtube.com/watch?v=u4ZHwphmYLU
Attribution
Myself, and countless hours of practice with @
CatcherAndTheRai