well PP IS in the MBR. (Marth Back Room) I'm in the Diddy Back Room, but Marth is my secondary and I'm trying to get into the MBR. Anyway, my point is I know quite a bit about each character, and how to beat them. Against a diddy, marth is going to tend to jump around like a spaz even more. He'll be using lots of dtilts, nairs, and fairs, and if you approach with an aerial, it will probably only work once per stock, and you'll have to trick him into thinking you're going to do something on the ground. After that he will just ftilt. You're going to have to use an intense combination of your peanuts, aerials, and forward b in order to keep your bananas unpredictable. Keep him on the ground if you can. However his weak spot is below him. Monkey flip kick will be the best offensive move for you, and it will outprioritize almost anything. Remember that he has no projectiles, but can outspace you. Don't try to space him, but play defensive most of the time and zone him while camping with your projectiles. Every once in a while you will see an opportunity to punish, and can follow up with a huge banana combo. DO NOT just spam the bananas. Don't try to punish him in his shield either, but you can try to wait for him to up b out of shield if he never shield grabs by just shielding. I would say to stay out of the upb's range, but it's deceptive, and will take you a few hits to get it.
, freaks out at right times 
