After about over 1000 hours of Splatoon playtime, I have come to this realization. Ranked is a Stacker Machine.
I've watched the videos. I've seen the strats. I've employed Offensive, Defensive, Support, and Objective Focused Roles. I've used all the weapons. I've gotten double digit K/Ds. I've avoided dying at all. None of these things will stop the constant losing streaks.
You notice that the developers are very concerned with keeping people playing the game? Well, Splatoon is designed with that in mind. I've noticed a pretty consistent trend of the matchmaking placing me in all around inferior teams, in terms of weapons and rank, leading to disproportionately long losing streaks. Consistently, i've seen a trend of my team being completely wiped at least 3 times a game. Why is this? Because the developers use the Ranking system as motivation for players to keep playing. They know that if players can reach S+, they will not have anywhere else to go. So the matchmaking creates a disadvantageous environment where it will put you on teams with the lowest kills/coverage/rank etc., in order to make it more likely you'll have to lose and try again. Some players are able to reach S+ because even if the chances of reaching S+ are low, they are still there. Just like how Stacker Machines still have a chance of winning. The fact is that Nintendo is a group of class-A video game designers, and as such, they know how to reach their development goals. In spite of all of these techniques,their design has grabbed me hook, line, and sinker. Kudos, Nintendo. I'll be there for another 4000 hours, hoping for that small chance i'll gain S+, just like you intended.
It's no secret around here that I've been involved in various topics trying to identify the inner workings of the matchmaking system for quite a long time. There are some very obvious signs and patterns that there's something not quite right with it, or that not all is as it seems, but though a number of us have tried, we've often fallen short in our assumptions - things didn't add up. For a while we presumed there was a simple Elo system in play and we were trying to explain the patterns through the randomness of Elo and how disastrious it woudl be applied to a team game with team scoring. But the way Elo would mess with the game don't seem to be applicable under closer observation. I no do not believe Elo is involved in any way, as W/L ratios would cause Elo to shift your standing and that doesn't seem to occur.
I'd considered the "stacker machine" idea that you put forth here. I don't believe that's quite it either, though I would NOT rule out that it is a component. Nintendo would have significant reason from a business AND a player experience standpoint of maintining the player base, and Nintendo is a master of fueling addictive behavior through gaming (video today, gambling yesteryear.) But as others here have said, if it were doing that it would make S and S+ more of a revolving door than it is. The players that get there and stay there and/or easily get back to it would not have such an easy time doing so if it were simply shifting people down to appeal to compulsive behavior (or at least not if doing so exclusively.)
I had also considered, and still don't rule out the potential that they were merely load balancing the limited population across the different ranks to ensure sufficient populations in each lobby. Again, that still might be a factor, but it doesn't explain some of the sudden swings.
Recently I believe I've made a breakthrough in understanding how things work. As I posted in the salt thread last week I had the interesting experience where, after a rotation change, I changed weapons to a midrange shooter from my usual chargers/brushes/rollers. As a result of not playing shooters much I was doing awful. With bamboozler I was going 13/6. With the shooter I was going 1/3, 3/5....I sucked...because it's not something I play. I was contributing fairly little. After 2 weeks of losing all too much and seeming fixated in A- (this is my 2nd alt) where I'd get to A-70 then lose to A-8 then A-70 then A-8 or thereabouts) suddenly I won EVERY SINGLE GAME all the way to A30. Most by KO. All while playing much WORSE than I had been due to using a weapon I'm largely unfamiliar with and never practice with the whole class.
Suck more, win more! Lead your team, lose. Contribute little, get carried by your team! Not quite. Then when I got to A the pattern resumed....win to 70, lose to 8, win to 70, lose to 8. Not always 70 and 8, but somewhere around that range. As others have observed it seems like it keeps trying to keep you in the rank you're in. That's commonly seen.
Now, the common thread here is "find ways to improve, if you're losing too much it's because you're contributing to the losses" blah blah, stuff that S+ ranked players around here can often point out. But what I've observed, is, in the losing streaks, I'm often the best at k/d on my team. I'm also the only one that seems focused on the objective at ALL. In the rounds i'm not the best k/d I'll have the teammate that went 12/10, I'll have the ones that went 9/6. But the catch is, in, say, Splatzones, while I was at the zone non-stop, I didn't see one of them, ever. I'd go 3/12 because I'd be divebombing the zone half the time, meanwhile my team was at the FAR corners in the side alleys in the enemy base. I'd watch them walk AROUND the enemy controlled zone....not to make a push from a different angle...but to simply go looking for foes to splat. Tower? Forget it. In such losing streaks I've seen horrible cases such as playing eliter on Moray. MORAY. I'd watch a blaster on my team on one of the little perches blast someone off the tower as it's parked right under his feet. Then ignore the tower and let it reset to mid. We spend half the game 98-40. The 2 points was me. Finally I gave up the sniping and just took up dedicated tower riding as the only player on my team willing to ride it. MANY of these games go 98-x. Or 100-x. NOBODY will ride the tower. Nobody will run the RM. So I become the dedicated rider/carrier. It really doesn't matter what weapon I play - I never use it, I spend the whole thing on the tower as the designated rider. As my team follws BEHIND the tower. But it doesn't matter. The 3 of them get wiped over and over and over anyway. Numerous RM rounds yesterday, I was the one that ran the RM. Didn't get KO but bot pretty darn far, teens/20's in Museum etc. I'd make the same run (alone with no escort of course) into the lead 2, 3 times a match. Push the lead further. Then in the last minute the team squanders the lead, slacks off, gets wiped during the enemy push. I can bail them out and kill the carrier once, twice, 3 times.....but eventually I'll falter...I'll get splatted first. And if I do, it's over, we lose the lead. So I did some experimenting. I took up krakon for a while. I just roamed around the edges and painted. Sure I splatted some foes when they came around. I chased them with a kraken a few times....but I didn't touch the RM at all. I didn't even help pop the shield. I didn't escort it. I stayed far away from it and did my own thing. MY W/L ratio was the same as if I'd participated! It didn't MATTER what I did - W/L was determined for me by the other 3. If I leave them on their own and don't try to carry them some of them seem to figure out they're on their own and THEY do it. The ones that don't are too bad to be carried anyway. The result is relatively similar. Then I was on a losing streak yesterday. Got to A+70-something or A+80 something 3 times yesterday. Then the losing streak down to A8. Then suddenly back to A80. On that winning streak to A80 I noticed that the tables were turned. My opponents had the trio of incompetents that I could slaughter over and over again and distract with the slightest feign....and one really good player that just couldn't carry them. 3 & 1. Always 3 bad and 1 good.
Now the above is not the CAUSE of the issues. It's the symptom. Watching the patterns, the types of team pairing which as you pointed out in your OP, the teams are AWFUL. The issue here is, it's not random. The losing streak where you are chained with bad players non-stop no matter the lobby. Random matchmaking can't work that way. It wouldn't be consistent. Then the winning streaks. Good players and/or bad opponents non-stop no matter the lobby. A few stray games here or there but generally it's continuous. random matchmaking, even broken matchmaking would not be so consistent in pairing all good or all bad players. This is intentional. There is no pattern to random matchmaking - this follows patterns.
My theory from all this and some extra data gathering not discussed in this text wall, in terms of the broad stroke of how ranked matchmaking works is thus: The ranking system does not work the way it makes you think it works. Most people here are assuming, it works as presented. That better players win more than they lose and can carry weaker teams and thus get more points and rank up. My theory is that's not accurate. Wins and losses are merely the tool used for allocating/removing points, but are not how your rank is determined. I believe your rank is determined behind the scenes, by invisible metrics gathering. If you are an A+ it's because the system has calculated you are an A+. It then hands you favorable team matchups or, at a minimum, doesn't interfere in your ability to win until you arrive at A+. Then once there it will hand you favorable/unfavorable matchups designed to keep you in that position it has determined is your real rank. If it recalculates that you're now an S, it will hand you favorable matches or stop restricting your ability to win through planned unfavorable matches until you arrive at S, then will return to alternating waves of favorable/unfavorable pairings to keep you maintained there. The reason the whole team is usually bad is because that whole team consists of players who have been slated to move down, likely against players who have been slated to move up. The more even hard contested matches are where all players are slated to stay in place. This facilitates the "losing streaks" from, say, upper A+ to mid to low A. It really rapidly moved you down a rank because the invisible system decided that you're now in that lower rank so it acted to quckly move you there....then keep you there until it decides you should move up or down.
This system makes sense in a lot of ways. It fits pretty much all the nonsensical holes and patterns that have been observed in matchmaking. it addresses the problem of how do you rate an individual players rank in a team scored game? Answer: You're not REALLY scored as a team, you're scored individually after all - the team score just distributes to points.) If this is true, this should also address the backlash from the S+ crowd who likes to say "if you're moving down it's because you're not doing well enough, don't blame your teammates etc, etc." There's some truth to what you guys are saying after all if this theory is true. It would mean your loss really IS because of your bad teammates, but also means the system INTENDED that to happen, they were the vehicle assembled to move you down with them to your new assigned rank, but that your new assigned rank was assigned to you based on the system's evaluation of your OWN skill - I.E. your teammates did not rob you, the system gave you the awful teammates because it decided the next lower rank is where you need to be moved to be in your right skill.
I.E. in that system, you're scored on your own merits, NOT your team wins/losses - the wins/losses are almost pre-determiend (when there's a wide skill gap) to make you win/lose to settle you in the "correct" rank for you based on your individual skill. So it really IS based on you and you alone. Not to say it's always correct of fair however (that's part 2.) To a degree it IS a single player game in terms of rank determination in this case.
So why is it the commentating, statically S+ players haven't experienced this? The ones with the "10 hours to S+ using only H3 Nozzlenose" videos? Simple. They're right, their skill earned them their spot. But not in the way they think it did in a way that's reasonable for them to comment on the effect on others. Whatever determines your rank calculated them as properly S+ early on. Therefore it presented them no undue resistance on their road to S+. That's not to say they didn't earn it through wins. They did. But they system didn't give them any stacked, rigged matches designed for failure to intentionally block them in S or A+ - it permitted them to advance naturally to S+ without forcing them down. But make no mistake, there ARE S+ players that the system reevaluates as S, or A+ and it WILL arrange similar bad matches to shove them back down. The ones who stay there have stayed within whatever parameters are used to determine rank.
If you are in S, and seem to be perpetually stuck in S with arranged losses to low S and arranged wins to high S. You probably have been determined by the system to be an S. Your'e not going to S+ (or A+) until it determines that you now belong in that bracket.
Now here's the trick and where it becomes unfair. What DOES it use to determine your rank? It's not k/d. As you pointed out playing as the top k/d in every lobby doesn't seem to move you ahead. Playing with trying not to get killed doesn't seem to reliably do it either. Neither does being the only one focused on the objective of the one who most often pushes it to the lead. So what DOES it use to calculate skill? I'm thinking it must be more metadata based. How many shots fired that landed hits, reaction times to events, things like that. more complex subtle things and without knowing what, there's no way to game the system, but there's also no way to work on what really affects it, too. The S+ players that tell you to get better obviously have the right responses built into their playstyle. Some of us who might be good players who can get results apparently do NOT have the right reactions built into our playstyles....so we confuse the system and it often doesn't know where to place us.
I'm no S+. Never have been, never will be. But the system can't seem to figure out if I'm S, A+, or A. Or B+ some days. It seems to shove me back and forth too often based on some random calculation. Considering in squads without artificially restricted teams I can do very well against S & S+ teams (or get shut out by others) I still believe in "real" skill I'm properly an S. But in terms of what the system MEASURES, and maybe lag affects it, I don't seem to always be according to how it counts (even when I'm leading the team.)
There's one other factor. The difficulty spikes. Yesterday struck again. The Sunday curse. Sunday afternoon suddenly it gets WAY more difficult. Or more specifically, it starts assigning me to lower ranks and forces me there through long series of unfavorable matchups. My suspicion is that your assigned "correct" rank is not a fixed value based on the data of the entire player base, but is basically using average values of the player base CURRENTLY ONLINE as the divisor. Thus, if many people jump online with much higher calculated skill relative to you on a given rotation or day, your relative rank is lower than it was 3 hours before when different people online - so you get forced down, only to get forced back up again a day or two later when the average ONLINE player skill is lower again. For the S+ folks at the top, your player skill is probably among the OVERALL top, so you never get forced down based on who is online.
The good news if this is all true is that your rank is NOT arbitrarily ruined by teammates. The bad news is the horrible appearance it gives, and possibly bad ratings for certain players with certain playstyles, leads to the intense frustration of seemingly undeserved losses and series of losses is built right into the system by the design of how it works.
But I am now quite convinced this is how it really works. Sadly I don't believe I'll ever figure out what metrics it actually uses to determine which rank you "should" be in.