The Fox MU is kinda sillly, but it's definately not unwinable.
We pretty much stalemate eachother.
Fox has very poor horizonal aerial control, but he has excellent landing punish game in the form of upsmash. The thing is, we can simply choose never to engage. You can either camp the ledge or constantly run away, but both chars have alot of trouble approaching eachother. I think that the olimar and Fox MUs share a lot of parallels.
Couple things to remember.
1.) Upsmash is 100% avoidable. Upsmash is a punish move, fox can't set it up without dair. If you never get hit by dair, never whiff aerials, and never drop shield within a specifc range, you should never get hit by upsmash. Be exteremely wary of attacking a grounded fox with aerials. Force him to fish for uairs and bairs.
2.) He utterly gts shut down when you camp the ledge, especially stages like halbred and delphino where lasers can peneterate the stage from below. If you are in kill range and he is not, even the MU by camping the ledge hard.
3.) Never challange dair. The risk vs return is never worth it, unless you are 100% sure you can beat it from the side never stay below fox.
4.) His safest approach is dashgrab. Change your spacing by constantly retreating while you spam lasers (pretty much reverse all of your groudned laser/gyro game)
5.) Ftilt is pretty safe except on PS. Use it to knock him off the stage, then option select him into running into bair or edge hogging him.
Let me go into more detail here.
Fox can never get on the stage from off the stage is you bair properly. Prevent him from phantasming back on the stage.
If he decides to phantasm to the ledge, focus on hitting of off the stage again. His main ledge game is phanstasm, ledge attack, rising fair and getup/roll.
Bair beats phantasm, resets getup, leads into grab from roll. You lose when he ledge attacks, sometimes fair.
Shielding near the ledge beats ledge attack, fair, leads into grab from getup. Phantasm/roll is safe against shield.
Spaced fsmash beats ledge attack and fair, resets getup. Roll is safe, you lose to phantasm.
Uptitlt can beat phantasm, and makes the other options reactable, but the knockback does not always lead into getting him off the stage.
If he just sits on the ledge, poke him with dtilt.
Try to call him on these situations, a gyro on the stage can stop phantasm which makes shielding and spaced fmashes very powerful.
6.) Always DI away. Fox's follow up game is extremely potent, we should not be looking to outspace him after we get grabbed/dashattacked. Just try to get as much distance from him and do not try to guess with airdodge to punish his followup.
Stages:
Starters - Avoid CS and BF. SV is evenish, try to CP to YI, PS1 and FD are risky.
His CP - Ban CS or BF.
Our CP - Delphino is really good, water leaves him really vulernable to strong gyros and dairs, recovering is nasty, walls lead to dtilt locks, laser peneterate from below the stage. Halbred is a bit riskier with low ceiling but theres a bunch of things that are amazing about that stage. Mainly that fox has trouble recovering on that stage. If you don't like halbred, frigate is always a solid choice, but they will probably ban frigate.
If they ban Delphino, Halbred or Frigate.
If they ban Frigate, go Delphino.
Any other ban, go to Delphino. (This is my opinion though)
Hope that helps.
