His wavedash distance is practically the whole stage on YS/FoD/BF so you can't really do that, especially on those stages.
Could you elaborate on what you end up losing to?
As for general advice, always uthrow. ALWAYS unless they are at a decently high percent and you can dthrow them far enough offstage to set up a clean edgeguard. His recovery is free once you have him far enough offstage to go out and hit him, especially if he needs to use side b. If you see him using side-b, just run off and intercept it. Luigi is one character that is much easier to edgeguard when he is above the stage imo. Really, the idea of separating him from the stage and using your sword to keep them separate until he dies is pretty straightforward in this matchup because he has awful air mobility, can't challenge your fair/uair's range with his aerials, and has a mediocre recovery. Just learn to cover his landing and edgeguard his recovery and he should die from about 2 solid hits per stock.
Yeah, totally agreed with the wavedashing comment, there's very limited ways to get outside of his wavedash on those stages. and as far as what i end up losing to... that's kind of a tough question, he racks up damage with stuff like his down b and his tilts and stuff, but i usually get killed by an usmash if my arial isn't spaced perfectly, or his damn fair if i don't recover off the ledge perfectly, or a lot of times i get nailed by his misfire, which, i'm sorry, but that happens way more than 1 out of 8 or whatever it is, and he's so damn lucky with it
. So i guess a lot of my losses are due to my recoveries and spacing not being perfect, which i've been working on.
As far as throwing, i uthrow if he's at low percent and not by the edge, but if he's at higher percent but not enough to be thrown off the stage from where i am, i either fthrow or dthrow, cause i feel like uthrowing at high percentages sends him too high and he's able to recover before i can follow up with another attack. And yeah, i'm pretty consistent with my edgeguarding attempts, they're not always successful, but I try every opportunity. when he's too far and has to side b his way back i usually end him unless he misfires, and then im screwed if i have anything over, like 70%. I don't uair as much as i should, so i'll definitely try that.
Keep luigi out. Space him out completely. It's hard for luigi to get inside vs marth, and that is his only chance.
You can't spam ANYTHING vs luigi. A random jab can easily be punished, so refrain from Yolo'ing fsmashes (he can wd oos shoryuken for starts). Play completely reaction-based. Abuse well timed dtilts, fairs, jabs, ftilts, etc to keep him away. In the air, tipper uair beats anything except for the most perfectly timed dair of all time.
When edgeguarding, always hit him out of his side-b. If you can't spike him or reverse up-b safely, hit him with a quick aerial shield breaker or non-tipper fair and get back to the ledge. On stage, against his up-b you can tipper dtilt or SHFFL a dair on his head, or grab ledge and invincible ledgehop dair him.
Don't forget grabs. You can't combo hard off of them but they do lead to follow-ups. Mainly they're important because at that point luigi has gotten too close and it's one of your last lines of defense before he combos you.
Be ready for luigi's ledgedash. Know the spacing where he'll be losing invincibility and always put a hitbox there or grab. Grab will literally suck him in like a vacuum. It's important to pressure him in the ledge, since on stage is his only shot.
Yeah, i've noticed spamming doesn't work, especially against luigi. I used to spam dtilt a bit and got punished over and over for that. as good of a move as dtilt is against luigi, he's so damn floaty and weird that he has, like 15 different options to punish every move i attempt, so if he knows what move im gonna use, it's over. I feel like i play reaction based against everyone i play, maybe that's why i lose a lot, haha.
What you said about edgeguarding is good, i think i try to spike too much and get punished for it. or end up timing it badly and end up unable to recover and kill myself. as you can see, im pretty new to the game, i just recently started using SHFFL arials, before that i wouldn't fast fall, or L cancel most of the time. quickly realized how important that is. How do you ledgehop dair? I know how to ledgehop, and i've tried dairing from ledge hop but it always lasted too long and i couldn't get back on the stage. Is there some other technique i need to use or was i just not being quick enough?
And yes, grabs i know are insanely useful with marth, i used to never be able to land grabs, but i've been practicing DDing into jump canceled grab, so i've gotten better at landing grabs. Are there any other tricks besides DDing grabs and the obvious timing grabs around delays from their moves that are pretty consistently successful with grabs?
Once he learns how to ledgedash without messing up and airdodging to his death half the time, i'll definitely try that out.
Thanks a lot guys! I'm pretty new to this level of smash like i said, and this being my first post on smashboards, it's awesome to have a place where i can get good advice from more experienced players