Marth can no longer combo as well as he did in melee and his grab range is not as large.
However, as a sword character, his main tools are still strong. If you’ve played Marth in melee then you might know about spacing. That’s the same goal you’re trying to achieve in Smash 4. You want to invalidate your opponent by walling them out with any combination of your grounded and aerial moves.
Once you’ve got them in shield, you can mix them up with shield breaker and grab.
If you break a shield, his shield breaker fully charged will usually kill even from center stage and low percents. I’d recommend practicing the spacing and percents that it will kill on different stages. You can also push them with Marths body if you walk slow enough to get them closer to the ledge.
Marths throw game is solid. His fthrow and bthrow are mostly to gain stage control. Uthrow is his main kill throw and will kill around 170% with no rage and as low as 130-150% with rage. Play around with different percents and characters to get a feel for when it kills. Dthrow is his main combo throw, and you can true combo bair and uair at lower percents, while being able to catch airdodges or chase their di/double jump at later percents.
Some of Marths weaknesses are: Some of his hitboxes don’t start or end when you expect them to, his sour spot hitboxes are neither strong or combo very well, Marth lacks hitboxes inside his body, so moves might miss if they’re too close, and the biggest one is the end lag on all his moves. I’ll explain what these weaknesses mean.
“Some of his hitboxes don’t start or end when you expect them to”
-Some of the animations on Marths moves look like they should hit but the hitbox is no longer active or hasn’t activated yet. Notable examples are his Jabs and uair. Jab 1 looks like it would hit very low, but if you try hitting a pikachu or diddy kong when they land, you’ll notice you won’t hit with jab 1. Similarly, jab 2 starts low, but doesn’t hit high. Uair looks like it would hit directly behind Marth but it actually ends 45 degrees behind him. There’s a hitbox visualization thread in the Marth forum if you want to see what I mean.
“his sour spot hitboxes are neither strong or combo very well”
- This means that contrary to how well Marth comboed in melee with sourspots, his sourspots now are mostly just missed tippers. In other words, you really just want to be landing tippers most of the time in this game. Marths sourspots can combo to an extent from low to mid percents, but these usually come in the form of landing aerials. A notable example is landing with sourspot fair or bair to combo into grab or dancing blade at low percents. However, at high percents and even mid percents, Marths sourspot will push the opponent too far to combo with, so you’re better off spacing for tippers whenever possible.
“Marth lacks hitboxes inside his body”
Similar to the problem with moves not hitting when they seem like they would, Marth lacks hitboxes in inside of him. This means if you don’t space properly, an opponent might be able to get inside of you and not get hit with your moves. As you play Marth more you might notice this happening a lot. An opponent versed in the Marth MU might even abuse this. The best way to circumvent this is by employing retreating attacks when you’re trying to wall them out. Using shorthop back and perfect pivots will benefit you greatly and ensure that you land your moves properly. You always want to visualize where you’re opponent might be and one of the best ways to do that is putting yourself in positions where it’s just a matter of reacting to what they choose and invalidate them with your sword.
“...end lag on all his moves”
This is his real weakness and why it sucks to mis space moves or have one of your attacks miss because of the hitbox. Most of Marths moves have a lot of end lag, and even your opponent rolling behind you to avoid the attack might get them a grab or a strong punish. You also might see this a lot playing Marth, but the answer is simple. Don’t just press buttons, know when it’s safe to throw out a move and space well by retreating your attacks with shorthop and perfect pivot. This just takes experience.
Finally, punish bad landings, laggy moves or spotdodges/rolls with dancing blade whenever possible.
There’s more that can be said, but for now this can get you started!