I think often times in marth ditto's both players try to go on the offensive,
At the beginning of the match chances are they're going to go for the grab
If you see them dash dancing a lot, or staying grounded, watch out for grabs, hell, predict a few
what are they going to approach with, a tilt? a dash attack? won't do much good at lower %'s.
If you see them jumping, they're going for aerials, which you can shieldgrab.
You don't always have to be on the offensive, and if you DI right their grabs won't lead into much, so definitely work the shield, especially if you notice they're getting offensive.
I definitely wouldn't advocate air to air combat, if you're opponent is taking to the sky's then stay grounded, marth is rather vulnerable from below, you can also CC to a decent % if you see he's going for a lot of fair's.
Nair counters spot dodges, to a certain degree, found this out myself recently, *******.
You pretty much need to find what stance your opponent is taking, and find the counter to it
As a samus main who faces a marth, and some times marth ditto's him (you've met him, zer0), a lot of my gameplan for vs. marth is to mess up his spacing and get grabs.
Save your jump when recovering, bair gimps hurt, and could cost you stocks and % that are very valuable.
Don't get caught on stupid platform ****, it's better to just get off of them safely than trying to punish your opponent, I've found light shielding works wonders and C stick to buffer a jump immediately after shield hit stun is a very safe way to get off platforms.
Wave landing off them on the way back down also helps quite a bit, but marth's range is a ***** to deal with, so come down slow, use your side B wisely, waveland and air dodge when it calls for it, if you can touch the ground, do so, but do it safely cause then you get your jump back which will come in handy for making it back on land.
Know your combo's on marth, and when you can't follow them up assume a good position. If he's in the air after you've got in the last hit you can, stay close to him, but keep distance, don't throw out attacks, a lot of people like to jump, count on this and go on the offensive when he's used his options (double jump/side B). If he is coming down and hasn't used his jump, feel free to shield, he can't grab you from the air.
Just remember that you don't always need to be attacking, remember to DI his fairs and Uairs and Utilts correctly or you'll gain a lot of %.
And his grabs as well.
Try to limit your Fsmashes and dash attacks, cause they will get you punished if the marth can WD OoS (I do it all the time, it's mad easy and satisfying to punish marths ****ing Fsmash)
Try to only Fsmash out of combo's, or when he's in the air, same with dash attack. If he has the ability to shield, the reward might not be worth the risk.
Also from 0% I'm pretty sure marth can
Grab
Fthrow
Regrab
Fthrow
Regrab
Fthrow
but it stops here.
Any hits following is poor DI/good reads.
If you are getting hit with Fsmashes then Di diagnally down and away from marth
