I find Marth can't take stage back so easily if he's somewhat or fully cornered, but otherwise agreed on giving up stage sometimes. And I've tried to mess with ASDI down while dashing but haven't found a good method so I'd love to be enlightened if someone knows one. The only time I can use ASDI down out of movement is when I know I'm somewhat outplayed and will be hit so I preemptively hold down early.ok so basically im on my phone traveling for the week so my typing is going to suck and idgaf.
playing against a given character in X vs Y as a MU is often some combination of "as X i should do <things>" and "i should do Y things against this character", ie you play partially for your character and against theirs. basic example lets say fox vs sheik, as fox you want to do shine > upsmash, and against sheik you want to abuse her poor approaches. to some degree the things youre doing will fit both but im trying to isolate the idea so go with it. marths tools are somewhat like CFs where theyre either incredibly good or totally dog**** but CF is more obvious about it. marth is ****ing amazing when his dashdancing is good or he can attack your attacks. against marth, it is generally better to pick the latter idea where you play against marth more than you play as your character. this is important, and once you have an idea of how to play against marth it will transfer between characters more than say the fox MU would.
the first rule of marth mirrors is to not jump. marth is incredibly good at killing and very poor defensively, his combo weight, recovery, oos options, etc are simply not that good. you should never put yourself in a position where the other marth can kill you for no reason and randomly jumping is a big one that people suck at. with two good marths this turns the game (correctly) into a strong dashdance mirror. in a dashdance mirror with fox CF marth, these characters take stage quickly and can randomly kill you for it, so its okay to dashdance "looser" and be a little bit more willing to forfeit small amounts of stage to avoid a proper conversion from the opponent. marth is well equipped to take stage back so the loss isnt so big a deal. as much as you definitely want to take stage, its okay and even preferable to not play tight as ****. third, in the DD mirror, because both players are moving you will frequently find that its hard for either player to land a proper hit. because of this, you will always want to have buffer for asdi down in and out of your movement so when you get clipped you can randomly grab them for it with a fake cc grab and kill them. this is particularly strong in the marth mirror because marth can get brutally punished even if he hits his attacks specifically because he landed the wrong part of the attack on the blade. sometimes in the marth mirror if i find that the other marth can dashdance as well as me i'll just let them hit me and kill them for it. not the best idea but you should be aware of it since the DD mirror basically nullifies true CC as an option (and if they try to true CC you, dashdancing and good dtilt use still beats it).
a really good marth mirror then becomes a really strange game where neither player ever blocks or dodges or jumps or true crouches, because all of them are bad vs good DD use. its just two players that never jump trying to grab or dtilt the dash away part of the DD and not landing good hits until one of them finally gets a good conversion and randomly murders the other on the spot.
will add more later but lets get a discussion going
@PPMD
I believe that a central role in Marth dittos is internalization of the rules you mentioned to the point you understand the exceptions well. Basically I believe jumping has its place to zone but even approach because the opponent is looking to Dtilt/grab the approach so much and you can move right over that by jumping. Not only does this complicate neutral more for your opponent but it makes your standard tools stronger. To me, a good Marth ditto is one in which both players understand the rules and have their own preferences with regards to breaking them. It's more dynamic and nuanced, but at the same time fueled by a strict building on top of the foundational Marth theory.
I know you more or less know this since you mentioned exceptions before, but I felt it important to bring up now.