We thankfully have a few, but they all aren't exactly character wincons as they are just extremely common player habits across R.O.B. mains.
I believe ROB does personally equally well in all states of disadvantage, but most will opt to go around the ledge if possible. Try to cover them going high and burn fuel the best you can. He does not get any until he touches the ground away and it takes a while to charge back.
We also have some neat 0tDs if you want to get fancy and grab gyro! Keeping gyro away from rob can also be valid if you arent comfortable using zcatches. Toss it up to get it away. Never offstage or at rob as itll disappear faster. It is important to learn how to catch gyro outside of dash attack/ a tilt as thats what they want to punish you.
Some characters can jump aerial it or landing aerial or wavedash/landing airdodge to catch it. Learn what works best for you!
For player habits there are four main ones. Nair, roll, shield, laser.
Nair: most ROBs will nair in the same spots, especially in disadvantage. It is normally close to the corner which really helps us because parry dtilt becomes a good kill move.
Roll: whenever pressured (especially on shield) robs will roll quite a bit. In the corner this includes roll in. Easy upsmash to cover it.
Shield: you can scare them into shielding and picking poor oos options or poking their shield for free once they are too scared to swing (or its a true poke from fair). Nair is extremely good with this pressure, especially spaced and cross up nair. Rob struggles to deal with this so itll often force a reaction.
Laser: robs will often laser in similar spots, even with bucket. The most common are from ledge and after gyro in neutral. Iirc strong kills at 0 and weak is in the mid %s
Mostly want to focus on the habits stated above + general projectile habits. Bair and bucket do amazing jobs at handling gyro while nair can often stuff or whiff punish most of his aerial buttons. Also see how he handles gyro. If he drops it a lot, expect dash attacks and stay out of that range, esp near ledge. Some will mash zdrop nair. Just hold shield 99% wont gyrohawk you and if they do you gotta try and stuff it. It is fairly telegraphed from how they set it up above you.
I honestly don't know how to describe this other than a bullet hell game where you have to rps once you get in (thankfully nair is a really good rock to throw). They have up close gyro shot, fair, nair, ftilt, dtilt, da, and ofc the normal shield and dash back. If you're getting tagged by bair, you probably are jumping in a bit too much and getting preemptively called out. (Or they are just mashing it to kill. This one makes it easier to stuff if close enough or parry punish). But good movement and awareness mostly fixes bair from being an issue if you are grounded. For the other options, different types of nair can win along with more specific options like pivot ftilt vs dash back, our bair vs their fair/gyro etc etc. You have to see what they want in this burst range because it often either lacks in disjoint or speed, both of which can be taken advantage of.
Genuinely the worst place for gnw to be. Rob has a few things he can do here. All cover different things.
Gyro at ledge: Well, if they roll in to toss gyro down, nair them before they can escape. This'll often win the interaction for us. Otherwise take the hit and reset. Sometimes drop down up b can work, but they can also just upair or bair you. Just be smart here. All other options are covered by the rob or the gyro. IIrc you can drop down dj zcatch with tight timing. Just know it can be punished and messing up ca be pretty bad.
Standing at roll: Tbh likely you can just jump and escape. Bair is pretty slow and fair won't do much if you do get hit much of the time so its a fine risk. Most other options can get gyro'd or upsmash'd on reaction. Mix up so you dont get preemptively bair'd but obv jump will do well.
Bair/Dair: Both of these hard call out stall from ledge and will often let him punish roll in for free because you can just drift to roll after. Obviously, don't roll. Pick any other option as the moves are about to start if possible to get away. Just dont drop down either because you get no iframes.
Nair: Low key if they spam nair at ledge we can nair it back. Otherwise a well timed get up attack or roll can be smart. Sometimes drop down up b too.
Shield: Dont swing on it. Oftentimes neutral get up will be grabbed as well. Roll can be fine if not in range and jump is obviously fine as it is unreactable.
Side B: Get up attack 🙂 also drop down dj nair can win if done early. Roll if theyre closer to ledge and heading offstage. Sometimes get up attack gets hit by the back part.
Dair is somewhat inconsistent vs him, but occasionally necessary to get him away. Try to disengage otherwise because you can die super early to rob upair. I usually try to get to a platform if possible. Otherwise mix up drift and your jump well.
Mix up up b timings to not get dair'd. Be wary of them throwing projectiles at you. Bucket is your friend here. Idt most will jump off after you. If so you can normally box them off or up b away.
Most will never go here. If they do watch for 4 options. Roll, drop down dj gyro, drop down dj laser, and jump nair.
Chef often catches all of these, but if you want to not chef to bait them into going here, this is what theyll often do. Sometimes maybe a neutral get up shield or dtilt. You can punish the regrab or them going high from here if their drop downs get shielded or reflected/absorbed. You can upsmash the roll and parry dtilt the nair.
They will all nair in the same spot in the corner to land at least once. Parry and punish it please. They have some b reverse stuff and stalling with up b/aerials. Just wait and let them burn gas until you are in a place to juggle. Now theyre getting juggled with less gas if sent offstage. Expect a lot of nair though. Sometimes a bair if you let them that close. Please parry the nairs.
I honestly try to cover high more than anything. Up bing right out of range with back turned is OP if you need to up b to chase. Lets us bair if they try to go back down while we can drift to ledge. If they keep going high its a free up air kill off the top. Making sure to FH offstage is a big part to catching high. If he goes low you want to drift around his buttons and poke at him with bair or up b if you can and not SD. Don't really have to KO outright, just burn fuel. That is usually the main goal here, burn all of his fuel so he can't make it back.