OK, so Diddy Kong is one that starts out feeling impossible and becomes more even as you learn the matchup. A few tips:
-Diddy Kong can glide toss your suit pieces. Get rid of two or be very careful because you do not want him to get a hold on them
- Diddy Kong needs his bananas to even begin to compete with your ground game, and his aerials do not compare at all. However, the bananas are a big deal and make approaching very hard. Taking control of these will help a lot. If you don't have control of the bananas or at least attempt to clean them up before approaching, this can get nasty fast.
- If the Diddy Kong you are facing has an amazing banana game and you just can't take control of them no matter what you try, the second best option is to just get rid of them. If you still can't do that, aerial approaches are the next best thing. SHAD+Buffered uair is awesome against Diddy Kongs that camp with bananas.
- As usual, you want to try to get Diddy Kong in the air. Dash Attack to buffered utilt or dtilt is a really good option. Uair>everything Diddy has in the air. With that said, Diddy Kong is not helpless in the air and if you're not careful you could get smacked in the face with a bair. I believe bair is his best kill move, as well, but it's slow. Your aerial game is better, but you need to learn how to use it.
- If you are getting ***** by bananas expect to get grabbed a lot. With that said, Diddy's grab range is not that good, and has some ending lag. Avoid and punish.
- ZSS has a really good banana game which you should take advantage of. There's a write-up I did here, if you're interested:
http://zsstech.blogspot.com/2009/06/zss-tech-blog-002-banana-tech.html
- Never recover low. It's really easy to get owned by the peanut popper gun or a dropped banana. Dont' laugh, it could happen to you. Flipstool off bananas and peanuts for extra horizontal recovery if he tries to toss them for a gimp.
- Dash Lock (duh, I had to mention it) on Diddy starts at 26% and makes for a very easy edgehog if you can pull it off.
-Gimping Diddy is pretty easy. If he gets knocked below the stage, grab the ledge and when he releases his up+b, drop off and up+b into the stage again. (Thanks to Snakeee)
- Finally, practice this match-up any way you can. It's one that will absolutely **** you if you walk into a tourney and don't know how to handle it.
With that said, I do think this matchup is roughly even if you know the fight and are very patient with your approaches and are paying attention to what the field looks like.
Good CPs are Lylat, RC, Norfair. Ban FD and probably Smashville.
I am calling this 45:55 for Diddy, but it's stage dependent. A good stage can shift it to your favor.