Adam v Gunhaver (Game 1)

-You attacked his current position multiple times at game start. On Yoshi's, attacking right off the bat can set a high-pace tempo and prove effective because the stage is too small for them to run away. However, in general you want to play it slow at first and wall a bit to let them know they can't just wait on you to come in to find their openings. It's a universally effective conditioning that works on passive and aggressive players alike. Play a measured first stock vs their character with whatever your neutral gameplan is for that matchup, then start to transition to your player reads as the match and set go on. In this example particularly, although attacking immediately is a nice mixup afforded by the size of Yoshi's, you drilled multiple times at Marth's current position when he had room to dashback. His Marth instincts should have told him to dashback grab at least one of those drills. Also, if shine will push them to the edge you should follow drill with grab. It true combos if you don't flub, and it's not like Marth has anything fast if you mess up anyway. You somehow landed the drill twice in a row, but got nothing off the subsequent shine as he fell to edge.

-You continue to drill his current position and now he's just hitting you with walling moves like fair as you come in. If you're going to drill, you have to be aiming at movement like dashback, dash forward, and wavedash back. It would also be a lot more useful if you set up some conditioning first, say by walling a couple times to make them think you won't approach - then coming in hot with a drill read on their dashdance.

-Failed usmash read on his movement as he comes off the edge. This would lose to pretty much everything Marth might do escaping the corner, including a spaced aerial, waveland up on the lip of the edge and fsmash you, and dashdance in the corner after getting up. He was also at 56%, so the usmash would lead to absolutely nothing. Much better corner pressure options from Fox are sh and fh bair, walk away utilt, really spaced dtilts, dashdancing until they whiff, and waiting a second then attacking them head-on with a nairshine or something. All situationally useful mixups, but usmash doesn't serve a purpose unless you have a definite read on a jump or initial dash and it would kill/combo. None of that applies to this situation.

-Soon after, you have him in the corner again and start dashdancing to see what he does. However, you dashdance inside his sh fair range and get hit. If you're going to wait someone out for observation or a whiff punish, it's critical to be at the right spacing - just outside the range of whatever the biggest attack is they're likely to use. Close enough to catch a whiff punish, but far enough you can't get outright hit. This idea applies to the whole game - being at the right spacing for the matchup at all times is an absolute necessity. But it's especially important for corner pressure because people like to attack out of the corner so often, and super especially important on Yoshi's because the whole stage is basically corner pressure.

-You're doing all this dashdancing without establishing why it should feel threatening. When you do attack out of it, it's at his current position and he's just walling you out on reaction. You have to condition your opponent if you want them to fear you, and you do that with safe options that cause a response. Examples include walling aerials (like Fox's fadeback bair or walk away utilt) that make them think you won't approach, ironically allowing you to approach; and attacking them a couple times in rapid succession, then backing up and punishing them for trying to attack you back.

-Seeing you fullhop out of pressure consistently, and his nairs are catching you. I doubt he picked up a read on the fullhop, more likely his own habit is to nair after his opponent when he has them pressured and your habit is incidentally losing to it. If you held shield or dashbacked as a mixup, you'd beat his nair. This is why it's crucial to see the game as all mixups, and to have mixups for everything. No one should ever beat you just because they pick up one read, or even worse if one of their own habits naturally counters one of yours.

-You fullhop out of pressure, run to the other side of the stage, turn around and run back in, then drill at his current position and get hit by a walling fair. Your neutral game needs conditioning tools to set up the approaches you want to do. This Marth has no reason to change what he's doing because you've given him no reason to feel like he should. What if you did that drill a couple feet back, outside his fair/grab range. He'd probably fair or grab, then you get to whiff punish his reactionary ass. That's the power of conditioning, it creates openings based on instinctual/emotional responses. Fiction complains about how Melee players still don't know what a bait is, and this is what he's talking about in his dumb way. The game played correctly is about setting up a bait, then going for a read - and always being ready to mix it up so they don't read you too.

-Get slideoff DI in your fingers, it would probably take 10 minutes. I need to as well. This Marth is getting utilts and uairs after uthrowing you to platform and you're not escaping. Every spacy I played at FB got slideoff DI on my platform techchases, so I had to read them with waveland grabs. You could google how to do it in 5 seconds, but I think you hold down on the c-stick and down and away on the grey stick or something. No more utilt utilt utilt combos would be pretty nice. Also works vs every other character, for example if Falcon stomps you on the plat you can slideoff DI at lower % and bair him.

-He has a fat lead, but you even it back up with your first approaching grab. You haven't grabbed before this moment actually lol. On Yoshi's, Fox's uthrow uair gains even more power because an uair chain can kill off the top at such low percents. He also blew an approach by trying to grab your current position without CONDITIONING first with a walling fair or something to make you unwilling to jump. You jumped over him, probably by instinct in reaction to him running forward, and started the pressure that resulted in his death. If he had just faired in front of you first, he might have avoided all of this and closed out the game. Conditioning and baits are everything.

-I'm watching you fullhop out of pressure while he nairs back and forth underneath you lol. That nair he was catching your fullhop with earlier is definitely just a habit, and it's incidentally missing your fullhops now - allowing you to win this game. If you had mixups on top of your defensive fullhop, you wouldn't have to essentially get lucky to avoid your opponent's own habits. Seeing the game as mixups and habits is critical to reaching the next level.

-Your usmash out of dashdance catches his nair habit. However, he previously happened to destroy you for the usmash. It doesn't seem like your usmash was a real read on his nair. This game is a lot of habits on both sides sometimes working and sometimes not, and it comes from you not seeing the game as a state of mixups deeply enough. It's all just rock paper scissors, but you're both playing in a dark room throwing rps randomly.

-He lands next to your shield randomly, and you die for your habit by fullhopping out of pressure right into a brainless fsmash. There's no way he had a soul read on your fullhop given his total lack of awareness thus far, so again you got unlucky for him to throw rock in that dark room while you threw scissors. If you only level up how you see the game, you'd destroy guys like this.

-You take his 3rd stock with an usmash read on a dashback, and this one I fully trust was intentional. You do pick up on habits well, but you don't give yourself a safe and structured space to download them from. It's more like you do things randomly until you happen to get a download, then it starts to go better. Instead, play the matchup according to a simple gameplan - safe, but threatening like walling aerials - watch what they do, then go for those reads now that they're conditioned a bit and you haven't thrown away your first 2 stocks to chaotic gameplay. In other words, play vs the character and give up very little until you're ready to play vs the player with your reads.

-You stay true to the habits you've shown thus far on the final stock, but so does he and he plays much more antsy than he did the first stock. The first half of the game was him standing in the corner walling while you attacked right at him without any baits - so he killed you. Then you catch up by finally using grab and going for dashback reads instead of just attacking his current position. Then it ends with him dashing in center stage while you usmash in neutral, fullhop out of pressure, and all the same things he could have ended you for if he'd picked up any read at all. Since he abandoned his (very simple) gameplan of walling under side platform, you had the freedom to take the game in a chaotic way. Neither of you were playing by a gameplan by the end there.