There are four kinds of hitstun. I'm just going to give them my own names for this guide. The first I will call true hitstun. This occurs when you hit with attacks that do not cause knockdowns/tumble. The second is tumblestun. This occurs when you hit them with attacks strong enough to cause tumble/knockdowns. You can use aerials and air dodge out of tumble stun after a set amount of time no matter how strong the move it. The third is meteorstun. When you use spikes that are strong enough to cause tumble/knockdowns you can meteor cancel them after a set amount of time with jump or up b. You could also air dodge and use aerials out of meteorstun but that is pretty silly. The last type is tripstun which is pretty self-explanatory. Tripstun is a fixed amount stun that usually gives enough time for the follow-up of your choice. Most moves have hitstun directly proportional to knockback so the best move for combos is one that has as little cooldown lag as possible.
This is what you are looking for. Here are some of the properties of true hitstun. True hitstun can last up to 30 frames after hitlag (when both the attacker and defender are frozen after a successful hit) is done and another bonus is that they can't DI the hit. The first hurdle in pursuing your combo presents itself. True hitstun does not last more than 30 frames. This means most of DK's attacks right off the bat are incapable of comboing. Any attack with more than 30 frames of lag after the attack hits can't combo via true hitstun.
Enough of the bad news. During certain %'s some moves will barely knock them off of their feet in a state of true hitstun. The opponent will stay in the air until the true hitstun wears off and be forced to land. This gives you 4-6 frames (depends on the character) of extra time to extend your combo. If they are hit during this brief period it does not show as a combo on the combo meter in training mode even though it is still a guaranteed hit. It is kind of like an "uncombo" in other fighting games.
Now the fun part begins. Using all of this insight into the combo system I came to the conclusion that Nair combos. That is right Nair can combo. When looking at its stats you notice that it has 15 frames of landing lag and it lasts a while. So to test out my theory I tried it out. Here are the results. At 35% Mario gets knocked off of his feet with the weak part of Nair. He gets 23 frames of true hitstun and 4 frames of landing lag. The true hitstun lasts until 62% and at that % it gives 30 frames of true hitstun and 4 frames of landing lag. At 63 % it causes tumblestun. On Mario the "combo zone" is 35-62% in vs mode. Hitting with the very end of his Nair leaves 12 frames of lag so that would leave you with a 15 to 22 frame advantage on Mario. That is a best case scenario and an unrealistic one. A more practical application would be to use FF Nairs. Nair has 15 frames of landing lag and because the hitbox is so terrible you only get a few frames of falling in between hitting someone and landing on the ground. It has 3 more frames of lag in the best case scenario but most of the time you will also take a few frames to land. FF Nair to Dtilt is guaranteed in the "combo zone" as long as you do it correctly (buffering the Dtilt and DI'ing the FF Nair so that they go in front of you instead of behind you). Towards the end of the combo zone you can reliably pull of Dsmash and if you are pro/lucky enough even punches/down b at the last few %'s.
The best part is that there is a combo zone for Bair, Nair, Ftilt, Dtilt, jab, Dthrow, Dtoss, and punches. The catch is that it is hard to exploit this combo zone for most of them without a wall to stop them from flying too far away. The combo zone also starts exactly when they can't trip anymore on flat ground. With Bair you get the best results when doing it right before you land or when you try to land a weak Bair by DI'ing into them while facing them. You are able to footstool them during true hitstun so Bair to footstool also works. Utilt and Uair hit them too high to force landings. AC Uairs and Uairs that land right after the hit are able to combo.
DK has two throws that are weak enough to have true hitstun (three if you count Bthrow at 0% lol). His regular Dthrow and his Dtoss (Cargo Dthrow) both have true hitstun until certain %'s. His regular Dthrow is very character dependent combo wise since they have different landing spots, weights, and the throw itself has different lag times for each character. His Dtoss is much simpler and gives a 4-7 frame advantage and forces them to land (Jiggs can jump at like 50+ but that's the only exception) until about 60%. It also doesn't stale so you don't have to take that into account either. If done next to a wall it is a free regrab on anyone including Jiggs (lol she could rest at 50+% I guess but with spacing you won't have to worry about that). His Dthrow has true hitstun until about 25% and gives a better frame advantage than his Dtoss. It will combo into Ftilt and Dsmash if they are close enough before it makes them tumble. At certain %'s on certain characters it can combo into down b (or punch if next to a wall). At 0% you can Bthrow to Utilt if there is a wall on some characters but that's pretty much it.
Tumble stun actually lasts longer than true hitstun but the fact that you can air dodge or attack out of it makes people think hitstun doesn't exist. You can't air dodge out of tumblestun for 13 frames after hitlag ends and you can't use aerials for 25 frames. You can't move, jump, or use specials for the entire duration of tumblestun. You can however DI the hit to change the angle the attack sends you in unlike true hitstun. The only attack DK has that can hit before they can air dodge is his second jab during the jab combo. This is the kiss of death for combos but this is where strings come into play. Even though they can air dodge before you can do anything, they become locked into their air dodge animation for at least 39 frames (most last 49 frames) unable to even DI. Say you Uthrow them and they air dodge your Uair at the last second. Because their air dodge lasts longer than your Uair you can just throw another one out there and it will hit them. They could also attack out of tumblestun but they have to wait longer. This is why double Bairs work so well. Unless they have a frontal aerial faster than your Bair they have to air dodge and when they do you can just throw out another Bair with a slight delay. Even if they do have a frontal aerial faster than Bair, they can't buffer it out of tumblestun so they need to have perfect timing and an aerial that is faster than your Bair. When you factor in that they also have to have enough reach with their attack to hit you, double Bairs become practically unpunishable when spaced and a reliable string.
Another example of a string would be Utilt spam. After it no longer has true hitstun they can air dodge and attack before your Utilt is finished. If they aren't knocked too high up, you are in a great position to react to anything they do. If they air dodge then you just delay the next Utilt. If they attack you can just shield it. Unless they have a really fast aerial and perfect timing they can't hit you before you can block. Even if they could attack before you can block you may end up knocking them high enough to make them whiff. It is kind of like tech chasing in that they have a chance to escape and that mindgames and quick reactions are what determines whether the next hit will land.
The rest of DK's throws always have tumblestun. The ones with the best follow-up potential are Utoss, Dtoss (stage spike), and Ftoss. Utoss has a -2 frame advantage on air dodges out of tumblestun and a +10 frame advantage on attacks out of tumbestun. This throw is better than Uthrow in almost every way for follow-ups. Jumping Utoss to DJ Uair is almost unavoidable on certain characters because you attack them before they can attack you and if they air dodge you can just throw out another one for a free hit. Ftoss has a -13 frame advantage on air dodges out of tumblestun and a -1 frame advantage on aerials out of tumble stun. Jumping Ftoss is useful when they have slow Fairs and Dairs because Uair is a pretty fast aerial and if you predict/react to the airdodge you can punish it. Dtoss stage spike on a stage like YI where you can't CSS them to death is useful because it leads into Bairs very well and puts them into a position like a jumping Ftoss would but much lower and with your back to them. It has a -10 frame advantage on air dodges and a +2 frame advantage on aerials so a lot of characters can't afford to attack or air dodge because they can't risk gimping themselves. Uthrow is only better than Utoss when there is a platform above you at low %'s since Uthrow doesn't throw them as high. They also might break out of a jumping Utoss if they are crazy at mashing at low damage.
Meteorstun is a subset of tumblestun. It is exactly the same except that you can meteor cancel with jumps/up b after 24 frames of falling. It doesn't work when you spike them on the ground though so when you Dair someone on the ground and they bounce up they can't up b you or anything like that. They can however still air dodge or use aerials out of it. The fact that they can't DI and are locked in their upwards momentum can lead to some decent punishment. DK can't really combo from meteorstun.
Trips induced by moves give 38-39 frames of tripstun. Dtilt trips are the best combo starter. This is pretty obvious but how good of a combo starter is may not be so obvious. Out of a Dtilt trip you can pull off side b's and Fsmashes guaranteed unless they get hit too far away. I never see anyone take advantage of that so I decided I'd mention that little tidbit. Trips off of Ftilts are not as good and only lead to Dsmashes at best so if you want something better you can tech chase them and try to land a side b/punch/Fsmash. Just before the combo zone %'s, most attacks have a slight trip chance. Stale punches can even trip at 0% which lead nicely into Dsmashes. Jabs at around 80-90% can trip which can be followed up with a fully charged punch (not tipper jabs though). Moves that can trip are also affected by the terrain. On upward slopes they can trip at higher %'s and on downward slopes they stop tripping at lower %'s.
Here I list the % when the combo zone starts and the % right before tumble starts on Mario when fresh. Stale moves and different weights shift the numbers around. Each move within the combo zone has 23-30 frames of true hitstun and forces them to land which is an extra 4-6 frames depending on the character. This is also based on flat terrain since slopes alter the %'s where they get knocked off their feet. On upward slopes they need more damage to knock them off their feet. Downward slopes would need less damage to kncok them off their feet. If you are trying to combo with weak Nair/Bair without landing then you want to hit with the very end of the attack (the end refers to timing not spacing). So with Nair you would want it to hit almost half a second after pressing A for instance.
Strong Bair- 7%.......24% (15 frames of landing lag or 23-24 frames of cooldown lag)
Weak Bair- 35%.......62% (15 frames of landing lag or 15-22 frames of cooldown lag)
Stong Nair- 12%.......32% (15 frames of landing lag or 26-28 frames of cooldown lag)
Weak Nair- 35%.......62% (15 frames of landing lag or 12-26 frames of cooldown lag)
Dthrow- 0%.......25% (Character dependent lag. 17 for Mario. More lag for heavyweights and less lag for lightweights)
Needs walls to really take advantage
Dtilt- 53%.......86% (15-16 frames of cooldown lag)
Ftilt- 26%.......48% (24-25 frames of cooldown lag)
Upwards Ftilt- 19%.......38% (24-25 frames of cooldown lag)
Downwards Ftilt- 31%.......54% (24-25 frames of cooldown lag)
Jab (non tipper)- 92%.......137% (19 frames of cooldown lag)
Aerial Punch- 0%.......8% (23-26 frames of cooldown lag)
Grounded Punch- 0% (Punch to Dtilt lock! Works on anyone Marth and heavier. This is the greatest thing ever btw)
Dtoss- 0%.......64% (23 frames of cooldown lag)
Utilt and Uair both cause tumblestun starting from 16% on Mario
Tipper jab combos into Dsmash as early as 110% on Mario (frame perfect)
So basically Nair can combo and Punch to Dtilt lock is the best thing since sliced bread on RC.
TRUE HITSTUN
This is what you are looking for. Here are some of the properties of true hitstun. True hitstun can last up to 30 frames after hitlag (when both the attacker and defender are frozen after a successful hit) is done and another bonus is that they can't DI the hit. The first hurdle in pursuing your combo presents itself. True hitstun does not last more than 30 frames. This means most of DK's attacks right off the bat are incapable of comboing. Any attack with more than 30 frames of lag after the attack hits can't combo via true hitstun.
Enough of the bad news. During certain %'s some moves will barely knock them off of their feet in a state of true hitstun. The opponent will stay in the air until the true hitstun wears off and be forced to land. This gives you 4-6 frames (depends on the character) of extra time to extend your combo. If they are hit during this brief period it does not show as a combo on the combo meter in training mode even though it is still a guaranteed hit. It is kind of like an "uncombo" in other fighting games.
Now the fun part begins. Using all of this insight into the combo system I came to the conclusion that Nair combos. That is right Nair can combo. When looking at its stats you notice that it has 15 frames of landing lag and it lasts a while. So to test out my theory I tried it out. Here are the results. At 35% Mario gets knocked off of his feet with the weak part of Nair. He gets 23 frames of true hitstun and 4 frames of landing lag. The true hitstun lasts until 62% and at that % it gives 30 frames of true hitstun and 4 frames of landing lag. At 63 % it causes tumblestun. On Mario the "combo zone" is 35-62% in vs mode. Hitting with the very end of his Nair leaves 12 frames of lag so that would leave you with a 15 to 22 frame advantage on Mario. That is a best case scenario and an unrealistic one. A more practical application would be to use FF Nairs. Nair has 15 frames of landing lag and because the hitbox is so terrible you only get a few frames of falling in between hitting someone and landing on the ground. It has 3 more frames of lag in the best case scenario but most of the time you will also take a few frames to land. FF Nair to Dtilt is guaranteed in the "combo zone" as long as you do it correctly (buffering the Dtilt and DI'ing the FF Nair so that they go in front of you instead of behind you). Towards the end of the combo zone you can reliably pull of Dsmash and if you are pro/lucky enough even punches/down b at the last few %'s.
The best part is that there is a combo zone for Bair, Nair, Ftilt, Dtilt, jab, Dthrow, Dtoss, and punches. The catch is that it is hard to exploit this combo zone for most of them without a wall to stop them from flying too far away. The combo zone also starts exactly when they can't trip anymore on flat ground. With Bair you get the best results when doing it right before you land or when you try to land a weak Bair by DI'ing into them while facing them. You are able to footstool them during true hitstun so Bair to footstool also works. Utilt and Uair hit them too high to force landings. AC Uairs and Uairs that land right after the hit are able to combo.
DK has two throws that are weak enough to have true hitstun (three if you count Bthrow at 0% lol). His regular Dthrow and his Dtoss (Cargo Dthrow) both have true hitstun until certain %'s. His regular Dthrow is very character dependent combo wise since they have different landing spots, weights, and the throw itself has different lag times for each character. His Dtoss is much simpler and gives a 4-7 frame advantage and forces them to land (Jiggs can jump at like 50+ but that's the only exception) until about 60%. It also doesn't stale so you don't have to take that into account either. If done next to a wall it is a free regrab on anyone including Jiggs (lol she could rest at 50+% I guess but with spacing you won't have to worry about that). His Dthrow has true hitstun until about 25% and gives a better frame advantage than his Dtoss. It will combo into Ftilt and Dsmash if they are close enough before it makes them tumble. At certain %'s on certain characters it can combo into down b (or punch if next to a wall). At 0% you can Bthrow to Utilt if there is a wall on some characters but that's pretty much it.
TUMBLESTUN
Tumble stun actually lasts longer than true hitstun but the fact that you can air dodge or attack out of it makes people think hitstun doesn't exist. You can't air dodge out of tumblestun for 13 frames after hitlag ends and you can't use aerials for 25 frames. You can't move, jump, or use specials for the entire duration of tumblestun. You can however DI the hit to change the angle the attack sends you in unlike true hitstun. The only attack DK has that can hit before they can air dodge is his second jab during the jab combo. This is the kiss of death for combos but this is where strings come into play. Even though they can air dodge before you can do anything, they become locked into their air dodge animation for at least 39 frames (most last 49 frames) unable to even DI. Say you Uthrow them and they air dodge your Uair at the last second. Because their air dodge lasts longer than your Uair you can just throw another one out there and it will hit them. They could also attack out of tumblestun but they have to wait longer. This is why double Bairs work so well. Unless they have a frontal aerial faster than your Bair they have to air dodge and when they do you can just throw out another Bair with a slight delay. Even if they do have a frontal aerial faster than Bair, they can't buffer it out of tumblestun so they need to have perfect timing and an aerial that is faster than your Bair. When you factor in that they also have to have enough reach with their attack to hit you, double Bairs become practically unpunishable when spaced and a reliable string.
Another example of a string would be Utilt spam. After it no longer has true hitstun they can air dodge and attack before your Utilt is finished. If they aren't knocked too high up, you are in a great position to react to anything they do. If they air dodge then you just delay the next Utilt. If they attack you can just shield it. Unless they have a really fast aerial and perfect timing they can't hit you before you can block. Even if they could attack before you can block you may end up knocking them high enough to make them whiff. It is kind of like tech chasing in that they have a chance to escape and that mindgames and quick reactions are what determines whether the next hit will land.
The rest of DK's throws always have tumblestun. The ones with the best follow-up potential are Utoss, Dtoss (stage spike), and Ftoss. Utoss has a -2 frame advantage on air dodges out of tumblestun and a +10 frame advantage on attacks out of tumbestun. This throw is better than Uthrow in almost every way for follow-ups. Jumping Utoss to DJ Uair is almost unavoidable on certain characters because you attack them before they can attack you and if they air dodge you can just throw out another one for a free hit. Ftoss has a -13 frame advantage on air dodges out of tumblestun and a -1 frame advantage on aerials out of tumble stun. Jumping Ftoss is useful when they have slow Fairs and Dairs because Uair is a pretty fast aerial and if you predict/react to the airdodge you can punish it. Dtoss stage spike on a stage like YI where you can't CSS them to death is useful because it leads into Bairs very well and puts them into a position like a jumping Ftoss would but much lower and with your back to them. It has a -10 frame advantage on air dodges and a +2 frame advantage on aerials so a lot of characters can't afford to attack or air dodge because they can't risk gimping themselves. Uthrow is only better than Utoss when there is a platform above you at low %'s since Uthrow doesn't throw them as high. They also might break out of a jumping Utoss if they are crazy at mashing at low damage.
METEORSTUN
Meteorstun is a subset of tumblestun. It is exactly the same except that you can meteor cancel with jumps/up b after 24 frames of falling. It doesn't work when you spike them on the ground though so when you Dair someone on the ground and they bounce up they can't up b you or anything like that. They can however still air dodge or use aerials out of it. The fact that they can't DI and are locked in their upwards momentum can lead to some decent punishment. DK can't really combo from meteorstun.
TRIPSTUN
Trips induced by moves give 38-39 frames of tripstun. Dtilt trips are the best combo starter. This is pretty obvious but how good of a combo starter is may not be so obvious. Out of a Dtilt trip you can pull off side b's and Fsmashes guaranteed unless they get hit too far away. I never see anyone take advantage of that so I decided I'd mention that little tidbit. Trips off of Ftilts are not as good and only lead to Dsmashes at best so if you want something better you can tech chase them and try to land a side b/punch/Fsmash. Just before the combo zone %'s, most attacks have a slight trip chance. Stale punches can even trip at 0% which lead nicely into Dsmashes. Jabs at around 80-90% can trip which can be followed up with a fully charged punch (not tipper jabs though). Moves that can trip are also affected by the terrain. On upward slopes they can trip at higher %'s and on downward slopes they stop tripping at lower %'s.
COMBO ZONE
Here I list the % when the combo zone starts and the % right before tumble starts on Mario when fresh. Stale moves and different weights shift the numbers around. Each move within the combo zone has 23-30 frames of true hitstun and forces them to land which is an extra 4-6 frames depending on the character. This is also based on flat terrain since slopes alter the %'s where they get knocked off their feet. On upward slopes they need more damage to knock them off their feet. Downward slopes would need less damage to kncok them off their feet. If you are trying to combo with weak Nair/Bair without landing then you want to hit with the very end of the attack (the end refers to timing not spacing). So with Nair you would want it to hit almost half a second after pressing A for instance.
Strong Bair- 7%.......24% (15 frames of landing lag or 23-24 frames of cooldown lag)
Weak Bair- 35%.......62% (15 frames of landing lag or 15-22 frames of cooldown lag)
Stong Nair- 12%.......32% (15 frames of landing lag or 26-28 frames of cooldown lag)
Weak Nair- 35%.......62% (15 frames of landing lag or 12-26 frames of cooldown lag)
Dthrow- 0%.......25% (Character dependent lag. 17 for Mario. More lag for heavyweights and less lag for lightweights)
Needs walls to really take advantage
Dtilt- 53%.......86% (15-16 frames of cooldown lag)
Ftilt- 26%.......48% (24-25 frames of cooldown lag)
Upwards Ftilt- 19%.......38% (24-25 frames of cooldown lag)
Downwards Ftilt- 31%.......54% (24-25 frames of cooldown lag)
Jab (non tipper)- 92%.......137% (19 frames of cooldown lag)
Aerial Punch- 0%.......8% (23-26 frames of cooldown lag)
Grounded Punch- 0% (Punch to Dtilt lock! Works on anyone Marth and heavier. This is the greatest thing ever btw)
Dtoss- 0%.......64% (23 frames of cooldown lag)
Utilt and Uair both cause tumblestun starting from 16% on Mario
Tipper jab combos into Dsmash as early as 110% on Mario (frame perfect)
So basically Nair can combo and Punch to Dtilt lock is the best thing since sliced bread on RC.
