My apologies if there was a thread export, I couldn't find one.
The approach:
This is where everyone struggles the most, but you honestly don't even have to memorize any timing! Dash towards ROB and watch his body very closely. Before both of his projectiles, he does some sort of motion i.e. lifting his head. That is when you shield cancel your dash, you will powershield him every time flawlessly. When you get to ROB, do NOT try to shield grab, you're asking to get punished bad. However, dedede has some very difficult to punish options at this point.
-Spaced Ftilt
It will trade hits with ROB's ftilt, which he probably isn't even going to use because of the worry of being grabbed, and it completely outranges the rest of his moves. Unless he tries to approach and powershield it, ROB cannot punish your ftilt from its farthest range, not even with projectiles as they are slower than your move.
-Short hop reverse bair
My favorite move in the game again. Here is another matchup where your bair completely beats all of your opponents aerials, except nair, which will clash with it only if you hit the very end of the nair, which you shouldn't try at high %! Remember to mix it up much like I pointed out against Marth when doing this, If ROB shields they're going to try to punish probably with an ftilt or grab, so utilize your jumps and dair his shield a few times before you land, orrrrr
-Swallow
All ROB can do about this is space an ftilt or fsmash you. If you're mixing up your air approach, don't be afraid to pivot a swallow after your bair or even just run right up to him and SH swallow. They're not going to see it coming for the most part unless you've already done it so it's free damage.
Where we win this matchup:
We gimp ROB almost as bad as metaknight does except we don't get a shuttle loops. There is almost absolutely no risk in going offstage and bairing everything ROB has. I cannot tell you how many times I have run a ROB out of fuel (**** those gas prices) because I kept bairing his up B. I get most of my damage on this and not on chaingrabs. Plus it makes them have to either grab the ledge, where you edgeguard ROB tremendously, or up B overhead, which is a grab opportunity on landing.
As far as edgegaurding goes, there are a couple things ROB will try while on the ledge.
-Sidehop fair
This can be beaten simply by throwing out a bair. ALSO, this is a killing opportunity! If you read the ROB doing this, and you shield it, you can uptilt right after. Too good
-Sidehope nair
I just downtilt it as I see it come out, easy as that.
-Side hop projectile
Just ftilt him if you see him trying to space to shoot you
-Get up attack
Free shield grab
When can I grab ROB?
The reason most Dedede players find this matchup even IMO is because they spend the whole matchup trying to grab ROB and end up getting punished over and over creating an illusion that ROB has a lot of stuff on Dedede. Simply put, don't think about the grab in this matchup. The only time you have it is if you powershield a drop Fair, a jab, an ftilt in close encounters, or shield his entire downsmash. These are very rare mistakes for a good ROB to make. If they make that mistake, cool, free chaingrab, if not, you need to play the way I've suggested.
Overall I would say 60:40 dedede or maybe even 65:35 dedede
The approach:
This is where everyone struggles the most, but you honestly don't even have to memorize any timing! Dash towards ROB and watch his body very closely. Before both of his projectiles, he does some sort of motion i.e. lifting his head. That is when you shield cancel your dash, you will powershield him every time flawlessly. When you get to ROB, do NOT try to shield grab, you're asking to get punished bad. However, dedede has some very difficult to punish options at this point.
-Spaced Ftilt
It will trade hits with ROB's ftilt, which he probably isn't even going to use because of the worry of being grabbed, and it completely outranges the rest of his moves. Unless he tries to approach and powershield it, ROB cannot punish your ftilt from its farthest range, not even with projectiles as they are slower than your move.
-Short hop reverse bair
My favorite move in the game again. Here is another matchup where your bair completely beats all of your opponents aerials, except nair, which will clash with it only if you hit the very end of the nair, which you shouldn't try at high %! Remember to mix it up much like I pointed out against Marth when doing this, If ROB shields they're going to try to punish probably with an ftilt or grab, so utilize your jumps and dair his shield a few times before you land, orrrrr
-Swallow
All ROB can do about this is space an ftilt or fsmash you. If you're mixing up your air approach, don't be afraid to pivot a swallow after your bair or even just run right up to him and SH swallow. They're not going to see it coming for the most part unless you've already done it so it's free damage.
Where we win this matchup:
We gimp ROB almost as bad as metaknight does except we don't get a shuttle loops. There is almost absolutely no risk in going offstage and bairing everything ROB has. I cannot tell you how many times I have run a ROB out of fuel (**** those gas prices) because I kept bairing his up B. I get most of my damage on this and not on chaingrabs. Plus it makes them have to either grab the ledge, where you edgeguard ROB tremendously, or up B overhead, which is a grab opportunity on landing.
As far as edgegaurding goes, there are a couple things ROB will try while on the ledge.
-Sidehop fair
This can be beaten simply by throwing out a bair. ALSO, this is a killing opportunity! If you read the ROB doing this, and you shield it, you can uptilt right after. Too good
-Sidehope nair
I just downtilt it as I see it come out, easy as that.
-Side hop projectile
Just ftilt him if you see him trying to space to shoot you
-Get up attack
Free shield grab
When can I grab ROB?
The reason most Dedede players find this matchup even IMO is because they spend the whole matchup trying to grab ROB and end up getting punished over and over creating an illusion that ROB has a lot of stuff on Dedede. Simply put, don't think about the grab in this matchup. The only time you have it is if you powershield a drop Fair, a jab, an ftilt in close encounters, or shield his entire downsmash. These are very rare mistakes for a good ROB to make. If they make that mistake, cool, free chaingrab, if not, you need to play the way I've suggested.
Overall I would say 60:40 dedede or maybe even 65:35 dedede