Since you guys haven't discussed anything for some days, maybe I can bring up another match-up? (I'm new, so I don't really know how these threads work :C, sorry).
But anyways, lately I've been having trouble with the Olimar match-up. I guess he could be taken care of with PK jumping and PK thunder, but all of his attacks seem to beat mine, specially the aerials. I've always thought Olimar is a very annoying character because of his great defensive game, but since I don't really know any Olimar I have very few (if any) experience with the match-up. What do you guys think?
One of my roommate last year played Olimar, and was really great with him. He used him really well, and at first, I had a hard time winning against him. He really owned me. But hey, I've found ways around his attacks, and at the end, Olimar was not that difficult. I would say it was pretty even.
First, never attack from above, his up-smash is awfully good.
Use neutral-air, a lot. It's a quick, free move and it kills pikmins. If he throws a pikmin, n-air, always. If he likes to spam-throw his pikmins, rush into him with n-air. You'll destroy his defenses in a matter of seconds. I swear, this move is a vaccine against pikmins. Short hop with n-air, don't go too far in the air.
PK Fire for space control. Aim the pikmins to create fire pillars. Don't be afraid to spam it, Olimar don't rush well. When you have fire pillars, it blocks its pikmins, giving you space to move around and to create more pressure.
If he's on the ground, stay on the ground. He have strong anti-air with Up-B, U-Smash and pikmin throw (Side-B? I forgot). Pressure his defenses, and rush when you can get close enough. Ness is better than Olimar at close range.
I'm a PK Thunder zealot, I love this move. But I don't recommend it against Olimar. When he's in the air, it's ok. When he's on the ground, the pikmins are always in the way. You can use it sometimes to change your approach, but it's not that good against a grounded Olimar.
If Olimar is in the air, well, destroy him. He have good moves, but Ness is a god-tier in the air. You have the advantage, so go for it.
Blue grab pikmin is fast, crazy reach and good. I hate his grab, it's so good, it's hard to believe. Be sure he don't have a blue pikmin in his line-up, because he will kill your rush instantly.
You need to be patient with this fight. Olimar is a fortress.
tl;dr
Your main moves are: N-Air, PK Fire.
Ground Olimar -> Stay on the ground.
Air Olimar -> Go kick his ***.
Pressure his defenses and contain him. When you have an opening, rush him. Kill with B-throw.