You sidestep SOOOOOOOOOOOOOOOO much, I'll **** you.
Also, you had a lot of momentum early on, and you were using lasers to bait approaches well (whether you noticed or not) I think what happened though, was the marth player started wising up and you couldn't really answer his change in strategy. If you pay attention, you get a lot more aggressive the farther you go into the match. ALSO, major issue was your positioning. Often times you would give up a solid position to get above marth, where all his priority lies.
Marth players will almost always try to break out of combos with a fair. BAIT THIS.
Also, in tournament, I would forgo the more technical option of drill/waveshining against the wall (not me personally, cause I'm confident) for a simple grab combo.
more up smash.
more nair into up smash.
more shine into up smash.
We'd have to play for me to get a good solid grasp.
Who played me @ pound 3 in fox dittos?
I haven't actually played this game in a while, so I'm gonna suck if I go to MA this weekend