Just yesterday, I managed to take first at a local tournament with a respectable tournout (between 65-70 players). As you can probably guess, I was using MK.
My most interesting and difficult matches were against a Snake, a Kirby, and another MK. I also had a fight against a Lucario (which wasn't very hard at all) but I still learned some things there. Here are my "findings."
Snake: Up-tilt is absurd. There's a reason people call him an MK counter. I was only barely able to win, and this is how:
I focused on getting the first hit and then running. By staying at the end of the level, I could react to grenades and fake-out Nikitas, meaning I never took damage from projectiles. This means I didn't have any control over the middle of the stage, but that's okay. Snake's dash-attack-up-smash cancel thing is really hard to deal with if he can pass by you when he does it. By staying at the side, he wasn't able to do it very effectively.
Another problem: anytime I tried to combo him, he'd mash B. A lot of times he'd get a grenade out and we'd trade. Even though I did more damage, this still put me at a disadvantage because Snake is stupidly heavy, and I was very light. By making him approach *me*, however, I could guess when he'd tilt or jab, and it let me play the defensive game. The trouble with running, however, is that you have to always have the lead, which is hard against a character who can do so much damage.
Up-tilt: Dealing with this move is hard. My first trick for dealing with it was using neutral+b; if you tap and hang outside his range, you can trick Snake into up-tilting and missing. Then you can move in, pop him up, and pressure.
The other trick is dashing-shield. If you make him tilt your shield, you can drop it and dash-attack -> up-tilt, dash grab, or if you're *really* close, down-smash.
You can't outrange it with down-tilt or forward-tilt (I don't know about down-smash). If he starts slowly walking towards you, you can generally guess that he wants to tilt you. Don't let him; powershield, dodge, roll, whatever, and punish the lag.
For edgeguarding, you can n-air and up+b him out of his own up+b. The problem is if he cancels and pulls a grenade, you'll trade and he'll get some extra bounce to make it back. When we played on Smashville though, I could use the platform to edgeguard extra aggressively.
Lucario: i didn't learn much, but I want to point out a few things. First is that it's (usually) really easy to guess when somebody will counter. Usually, they come straight at you even when you could easily hit them first. This is because they *want* you to hit them. So don't. Run at them and throw up your shield (just to be safe), and trick them into countering, then get a free hit.
Lucario's down-air has really good horizontal range beneath his feet. It's weird. His up-smash also has a strong hitbox behind Lucario at the end of the animation. It's hard to describe, but I watched this same Lucario KO somebody when they ran in behind his up-smash.
Kirby: Kirby is an interesting fight; you have the slight edge almost everywhere, but if you aren't on your game and the Kirby is, he can make things even. He can very easily forward-smash through your tornado, and since it's so strong, you have to be very careful not to spam it.
Don't approach Kirby on the edge. There's no reason he should get a suicide suck, and if he has the edge he can start spamming up+b and canceling it. Be patient and wait for him to come back. If he has a percent/stock lead, then you can often bait a response using dashing shield; shield drop into a strong attack and try to get him off that edge.
MK: Dittos are hard
and the MK I played was also good. The way to win this fight is to know what moves beat what other moves, and just guess what he'll do.
Forward-tilt, forward-air, and b-air: All of these beat the tornado.
Forward-tilt and down-smash beat an MK who dashes in.
Down-smash can be punished with another down-smash if you powershield. Otherwise, your best bet is to retreat or use a tornado (if you think he'll dodge afterwards).
Dash-attack -> up-tilt only works at around 30-40 percent; otherwise he can neutral-air you out of it.*
Rolls are very punishable: if you think he'll roll away, dashing up-smash or dash-attack. If you think he'll roll towards you, short-hop into neutral-air.
Almost nothing beats shuttle loop. If you think he's going to do it, don't challenge it.
*This lets you do a neat trick, however. If you dash attack, shield right afterwards; if the other MK tries to n-air or d-air, you can get a shield grab or shield-drop into an attack. In fact, something neat I did in an MK ditto was this:
Dash-attack, shieldgrab into down-throw, dash-attack -> up-tilt. I landed the actual combo by guessing how he'd try to get out of it, then doing it a moment later. By then, he was damaged and it was inescapable.
A final interesting fact about the ditto: I managed to get two kills by edge-hogging. This happened when he used both up+b and forward+b. His MK went into freefall kind of high above the level, and I waited for him to go to the edge. At the last moment, I ran off and grabbed the side, taking the edge from him and KO'ing him. I got stocks at 60 and 16 percent like this.
The reason I bring that up is because I think a lot of MK's try to get the edge after using certain moves. This can be safe, but also dangerous--the situation I described above is demonstrative of that fact.
Other general notes: A lot of MK's seem to have trouble KO'ing, but I don't. This is because at around 60-70 percent, I start grabbing and tornado'ing *a lot*. The goal is to reduce the decay on shuttle loop, glide-attack, neutral-air, and down-smash. Once the enemy is around 100+, you can start using your KO moves and they'll be refreshed, ready for action. I rarely have opponents who live past 140, and that doesn't take into account edgeguards and stage-spike KOs.
Also, forward-smash is really good because it pulls you back a little before you swing. You can trick people into attacking and then make them miss a tiny bit, landing your powerful forward-smash.
I hope all of that was interesting and helpful.
My most interesting and difficult matches were against a Snake, a Kirby, and another MK. I also had a fight against a Lucario (which wasn't very hard at all) but I still learned some things there. Here are my "findings."
Snake: Up-tilt is absurd. There's a reason people call him an MK counter. I was only barely able to win, and this is how:
I focused on getting the first hit and then running. By staying at the end of the level, I could react to grenades and fake-out Nikitas, meaning I never took damage from projectiles. This means I didn't have any control over the middle of the stage, but that's okay. Snake's dash-attack-up-smash cancel thing is really hard to deal with if he can pass by you when he does it. By staying at the side, he wasn't able to do it very effectively.
Another problem: anytime I tried to combo him, he'd mash B. A lot of times he'd get a grenade out and we'd trade. Even though I did more damage, this still put me at a disadvantage because Snake is stupidly heavy, and I was very light. By making him approach *me*, however, I could guess when he'd tilt or jab, and it let me play the defensive game. The trouble with running, however, is that you have to always have the lead, which is hard against a character who can do so much damage.
Up-tilt: Dealing with this move is hard. My first trick for dealing with it was using neutral+b; if you tap and hang outside his range, you can trick Snake into up-tilting and missing. Then you can move in, pop him up, and pressure.
The other trick is dashing-shield. If you make him tilt your shield, you can drop it and dash-attack -> up-tilt, dash grab, or if you're *really* close, down-smash.
You can't outrange it with down-tilt or forward-tilt (I don't know about down-smash). If he starts slowly walking towards you, you can generally guess that he wants to tilt you. Don't let him; powershield, dodge, roll, whatever, and punish the lag.
For edgeguarding, you can n-air and up+b him out of his own up+b. The problem is if he cancels and pulls a grenade, you'll trade and he'll get some extra bounce to make it back. When we played on Smashville though, I could use the platform to edgeguard extra aggressively.
Lucario: i didn't learn much, but I want to point out a few things. First is that it's (usually) really easy to guess when somebody will counter. Usually, they come straight at you even when you could easily hit them first. This is because they *want* you to hit them. So don't. Run at them and throw up your shield (just to be safe), and trick them into countering, then get a free hit.
Lucario's down-air has really good horizontal range beneath his feet. It's weird. His up-smash also has a strong hitbox behind Lucario at the end of the animation. It's hard to describe, but I watched this same Lucario KO somebody when they ran in behind his up-smash.
Kirby: Kirby is an interesting fight; you have the slight edge almost everywhere, but if you aren't on your game and the Kirby is, he can make things even. He can very easily forward-smash through your tornado, and since it's so strong, you have to be very careful not to spam it.
Don't approach Kirby on the edge. There's no reason he should get a suicide suck, and if he has the edge he can start spamming up+b and canceling it. Be patient and wait for him to come back. If he has a percent/stock lead, then you can often bait a response using dashing shield; shield drop into a strong attack and try to get him off that edge.
MK: Dittos are hard
Forward-tilt, forward-air, and b-air: All of these beat the tornado.
Forward-tilt and down-smash beat an MK who dashes in.
Down-smash can be punished with another down-smash if you powershield. Otherwise, your best bet is to retreat or use a tornado (if you think he'll dodge afterwards).
Dash-attack -> up-tilt only works at around 30-40 percent; otherwise he can neutral-air you out of it.*
Rolls are very punishable: if you think he'll roll away, dashing up-smash or dash-attack. If you think he'll roll towards you, short-hop into neutral-air.
Almost nothing beats shuttle loop. If you think he's going to do it, don't challenge it.
*This lets you do a neat trick, however. If you dash attack, shield right afterwards; if the other MK tries to n-air or d-air, you can get a shield grab or shield-drop into an attack. In fact, something neat I did in an MK ditto was this:
Dash-attack, shieldgrab into down-throw, dash-attack -> up-tilt. I landed the actual combo by guessing how he'd try to get out of it, then doing it a moment later. By then, he was damaged and it was inescapable.
A final interesting fact about the ditto: I managed to get two kills by edge-hogging. This happened when he used both up+b and forward+b. His MK went into freefall kind of high above the level, and I waited for him to go to the edge. At the last moment, I ran off and grabbed the side, taking the edge from him and KO'ing him. I got stocks at 60 and 16 percent like this.
The reason I bring that up is because I think a lot of MK's try to get the edge after using certain moves. This can be safe, but also dangerous--the situation I described above is demonstrative of that fact.
Other general notes: A lot of MK's seem to have trouble KO'ing, but I don't. This is because at around 60-70 percent, I start grabbing and tornado'ing *a lot*. The goal is to reduce the decay on shuttle loop, glide-attack, neutral-air, and down-smash. Once the enemy is around 100+, you can start using your KO moves and they'll be refreshed, ready for action. I rarely have opponents who live past 140, and that doesn't take into account edgeguards and stage-spike KOs.
Also, forward-smash is really good because it pulls you back a little before you swing. You can trick people into attacking and then make them miss a tiny bit, landing your powerful forward-smash.
I hope all of that was interesting and helpful.