I'm going to agree, in general, with many of the things Awex said.
As Sockz posted earlier, both characters beat up on each other pretty badly.
I don't know why I put that on its own line. But I did, for some reason.
I read somewhere in the last page or two that Olimar gets gimped? Not very true. The most we can do is apply lots of back and neutral aerial pressure offstage to try and either force him to whistle when doing so would leave him unable to use his Up+B to recover or to actually physically force him out of range of a successful Up+B for him. Baiting whistles can sometimes work to your advantage, but that's more of a mental pressure game than your typical "mindgame." There's also the very rare edgeguard--I haven't been keeping up with the Olimar boards, so I don't know why sometimes, even when he's not being edgeguarded, his Pikmin just kinda...plop themselves against the edge instead of grabbing it. This happens, too, on occasion, but I wouldn't rely on it.
Captain Olimar has a very weird edgeguarding game himself. His aerials are all very strong and break the jump relatively early compared to most other characters. He puts himself at risk while edgeguarding, though, since the whistle is mostly a defensive tactic and obviously cannot be used while using another attack. Yoshi's defensive attack options while recovering outrange Captain Olimar most of the time, but the speed and power of his Pikmin threaten ties if any player is not completely on the mark.
As far as KOs in general go, I tend to agree that Yoshi should not be using up aerial very often in this matchup. Unless you've got some sort of master plan and just want to bait whistles to set up for something else (which is entirely possible), up aerial will not really connect successfully unless you are applying massive pressure with things like single hit back aerials and weak up tilts or punishing baited airdodges. KOing off the sides for Yoshi is harder, but much more successful, I think--KOing Olimar off the top is really easy, but it's often stuffed by whistle since our upward KO attempts are fairly obvious (the moves, rather...not necessarily how we use them).
I don't think that Captain Olimar's upsmash KOs "early," per se, but I do find it extremely effective and spammable, especially out of a dash. Forward smash is the typical keep away-KO move, which is awesome, but there are dodging patterns that I've noticed Yoshi can employ to successfully dodge two and counterattack with jabs or tie on the third with forward tilt. It only works for two forward smashes in a row at the same speed, so it's not entirely "staple" to employ, but it's hard to explain without a video or frame data. I think Olimar players rely on passive damage and damage over time as the match goes on, and rightfully so. I don't think that Captain Olimar does enough damage straight up (it's just not built into his character, I find) to KO straight out of a fight. He has to set up over the course of about forty seconds or so can has to force opportunities, similarly to Yoshi. He cannot expect them to appear--he has to force them.
Olimar's forward air is good, but I think back air gets the nod for best KO aerial he has.
I also find it very hard to swallow Olimar's neutral air to smash as an effective technique--effective enough to use more than once, I mean. Similarly to how Yoshi players may have player-specific setups into effective KO moves, neutral air isn't exactly all-purpose for Olimar. Would its use not become very...forseeable after the first attempt?
As for camping, Olimar is quite top tier. I can't argue that. I will say, however, that people tend to let themselves get grabbed a lot by Olimar. Conversely, they try too hard to dodge and beat Pikmin tosses when they are eventually setting themselves up for ground **** (while they're trying to stop Pikmin in the air). I don't think taking some passive damage via Pikmin is entirely unreasonable unless it's that white one. They're easy enough to get off while approaching Captain Olimar and they do not apply freeze frames to Yoshi (if they did, it would be super gay and way too good).
I've already explained how to egg roll versus Captain Olimar--I received no disagreements with my post. I know it's probably not 100% on the money, but I feel that effective egg rolling makes this matchup so much easier. Similarly, proper downsmashing after egg lays (easy to do while DJing through forward smash spam) makes the matchup much easier as well. The only Pikmin that I notice that tend to survive are the purple one (obviously) and the blue one after the downsmash has degenerated by approximately two levels. Even if multiple Pikmin survive, I think Olimar only really becomes vulnerable when he has less than two Pikmin out. When he has less than two, his options become severely limited due to the fact that both players know exactly what Olimar's attacks are now capable of, instead of trying to keep track of two or more different kinds. With one or none, Yoshi can begin to apply smart, poking, lagless pressure and maybe not guarantee a stock, but at least make the next few moments very not easy for the opposing player. Anybody would be able to tell you that Olimar will make grabs a top priority at this point; knowing how to abuse that will make applying short stabs for pressure easy since lots of smart players know when to poke and when to back off. Sorry if that was a little incoherent, but I hope you all caught my drift.
Olimar's up aerial is good. It sure as heck doesn't juggle, though.
When we give a ratio for this matchup, I don't think it's more about whose advantage this is, as I think they're pretty close on paper. In a tournament situation, though, I think Yoshi has to do less work to see marginally better results over an extended period of time with more favorable stages. The ratio, to me, signifies who has an easier time of executing their battles plans and I feel Yoshi trumps Olimar, even if just a little bit, on that point, as I've attempted to outline above.
**goes back to the blue corner and waits for round two**
